Answer:
0.272g
Explanation:
To calculate the mass of oxygen collected, we can calculate the number of moles of oxygen collected and multiply this by the molar mass of oxygen.
To calculate the number of moles of oxygen collected, we can use the ideal gas equation I.e PV = nRT
Rearranging the equation, n =PV/RT
We now identify each of the terms below before substituting and calculating.
n = number of moles, which we are calculating.
R = molar gas constant = 62.64 L.Torr. K^-1. mol^-1
V = volume = 500ml : 1000ml = 1L, hence , 500ml = 500/1000 = 0.5L
T = temperature = 25 degrees Celsius = 273 + 25 = 298K
P = pressure. But since the gas was collected over water, we subtract the vapour pressure of water from the total pressure = 642- 23.8= 618.2torr
We substitute these values into the equation to yield the following:
n = (618.2 × 0.5) ÷ ( 62.64 × 298)
n = apprx 0.017moles
To calculate the mass of oxygen collected, we need the atomic mass of oxygen. = 16 amu
Thus the mass of oxygen collected = 0.017mole × 16g= 0.272g
To find the mass of oxygen collected over water, we can use the ideal gas law equation and the given values of total pressure, volume, temperature, and vapor pressure of water. By rearranging the equation and calculating the number of moles, we can then determine the mass of oxygen using its molar mass.
Explanation:To find the mass of oxygen collected, we need to use the ideal gas law equation, PV = nRT, where P is the total pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
First, we need to convert the temperature from Celsius to Kelvin by adding 273.15: 25°C + 273.15 = 298.15K.
To calculate the number of moles, we need to subtract the vapor pressure of water (23.8 torr) from the total pressure (642 torr) to obtain the partial pressure of oxygen: 642 torr - 23.8 torr = 618.2 torr.
Now we can rearrange the ideal gas law equation to solve for n:
n = (PV) / (RT) = (618.2 torr * 0.5 L) / (0.0821 L·atm/mol·K * 298.15K)
Using this value of n, we can calculate the mass of oxygen using the molar mass of oxygen (32 g/mol):
mass = n * molar mass = 0.0126 mol * 32 g/mol = 0.4032 g.
The value of ΔG°′ for the conversion of glucose-6-phosphate to fructose-6-phosphate (F6P) is +1.67 kJ/mol. If the concentration of glucose-6-phosphate at equilibrium is 2.05 mM, what is the concentration of fructose-6-phosphate? Assume a temperature of 25.0°C.
Answer:
1.04 mM
Explanation:
The conversion reaction given is reversible, and for reversible reactions, the free-energy can be calculated by:
ΔG = -RTlnK
Where R is the constant of the gases(8.3145 J/mol.K), T is the temperature( 25°C + 273 = 298 K), and K is the equilibrium constant.
K = [F6P]/[glucose-6-phosphate]
Because T = 25ºC, ΔG = ΔG°' = 1670 J/mol
1670 = -8.3145*298*ln[F6P]/2.05
-2477.721*ln[F6P]/2.05 = 1670
ln[F6P]/2.05 = -0.6740
[F6P]/2.05 = 0.50966
[F6P] = 1.04 mM
Which of the following shows the correct units for acceleration?
kilometers/second km/sec
meters/second m/sec
seconds/meter squared sec/m2
meters/second squared m/s2
Answer:
The correct answer is meters/second squared m/s2
Explanation:
Acceleration corresponds to a magnitude of vector type, is the relationship between a delta velocity and a delta time. The speed has units of m / second, km / second, km / minute for example, and time in seconds, minutes, etc.
Acceleration is measured in meters per second squared (m/s2), indicating the amount an object's speed changes every second.
Explanation:The correct unit for acceleration is meters/second squared (m/s2). Acceleration is the rate at which an object changes its velocity. This means it's measuring how quickly an object's speed or direction of motion changes in a given period of time. In physics, the primary units are typically expressed using meters for distance, seconds for time; thus, it's in terms of how much the speed (meters / second) changes every second, leading us to meters/second squared.
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A 2.21-kg piece of copper metal is heated from 20.5°C to 126.4°C. Calculate the heat absorbed (in kilojoules) by the metal.
Answer:
The heat absorbed by the metal is 91.27 kJ.
Explanation:
This is a sort of excersise about calorimetry which formula is:
Q = m . C . ΔT
where Q = heat
where m = mass
where C = Specific heat
ΔT = T° final - T° initial
You can find specific heat in tables, if you don't know it. It is generally given in the statement unless, you have to find it out.
Specific heat for copper is 0.390 kJ/kg.°K
Notice that units in specific heat are in °K, but it is the same K or C.
The difference doesn't change the sense of units. We can use °C.
Q = 2.21 kg . 0.390 kJ/kg.°K (126.4°C - 20.5°C)
Q = 91.27 kJ
Final answer:
The copper metal absorbed approximately 898 kJ of heat when its temperature was increased from 20.5°C to 126.4°C.
Explanation:
To calculate the heat absorbed by a substance when its temperature changes, we can use the formula:
Q = mcΔT
where ΔT is the temperature change, m is the substance's mass, c is its specific heat capacity, and Q is the heat absorbed.
The specific heat capacity of copper (c) is approximately 0.385 J/g°C. We need to use the mass (m) in grams and the temperature change (ΔT) in Celsius.
First, we convert the mass from kg to g:
2.21 kg = 2210 g
Then calculate the temperature change (ΔT):
ΔT = Final temperature - Initial temperature
ΔT = 126.4°C - 20.5°C = 105.9°C
Now, we can calculate Q:
Q = (2210 g)(0.385 J/g°C)(105.9°C)
Q = 897993.35 J
Q = 897.99335 kJ
Q ≈ 898 kJ (rounded to three significant figures)
So, the copper metal absorbed approximately 898 kJ of heat when its temperature was increased from 20.5°C to 126.4°C.
Lithium and fluorine undergo ionic bonding. Using the noble gas electron configurations for each (below), please explain the process of bonding step by step, using proper grammar and mechanics. Noble Gas Electron Configurations:________ Lithium:_______ [He] 2s1 Fluorine:______ [He] 2s22p5
Answer:
Lithium loses one electron to fluorine and forms ionic bond, having formula [tex]LiF[/tex].
Explanation:
Lithium is the element of the group 1 and period 2 which means that the valence electronic configuration is [tex][He]2s^1[/tex].
Fluorine is the element of the group 17 and period 2 which means that the valence electronic configuration is [tex][He]2s^22p^5[/tex].
Thus, lithium loses 1 electron and become positively charged. Fluorine on the other hand accepts this electron and become negatively charged. This is done in order that the octet of the atoms are complete. These both ions then form ionic bond as their will be electrostatic interaction between the two oppositely charged ions.
Thus, the formula of calcium chloride is [tex]LiF[/tex].
Ionic bonding between Lithium and Fluorine involves transferring 1 electron from Lithium to Fluorine, resulting in Lithium becoming a positive ion and Fluorine becoming a negative ion. This creates an electrostatic force that forms the bond. Both elements reach a stable electron configuration resembling those of noble gases.
Explanation:The process of ionic bonding between Lithium (Li) and Fluorine (F) involves the transfer of electrons. In the noble gas configuration, Lithium has 1 electron in its outer shell and Fluorine has 7. For both elements to reach a stable state (similar to that of noble gases), Lithium needs to lose 1 electron and Fluorine needs to gain 1.
When these elements come together, Lithium donates its 1 electron to Fluorine. Now, Lithium has no electrons in its outer shell and is left with the inner shell that resembles the electron configuration of Helium (He), a noble gas. Fluorine, on receiving the electron from Lithium, now has 8 electrons in its outer shell and resembles the electron configuration of Neon (Ne), another noble gas. So, both have achieved a stable state.
On losing 1 electron, Lithium becomes a positively charged ion (Li+) and Fluorine, on gaining 1 electron, becomes negatively charged (F-). This creates an electrostatic force between the two ions and they stick together, resulting in an ionic bond.
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The synthesis of methanol from carbon monoxide and hydrogen gas is described by the following chemical equation:
CO(g)+2H2(g)?CH3OH(g)
The equilibrium constant for this reaction at 25 ?Cis Kc=2.3×104. In this tutorial, you will use the equilibrium-constant expression to find the concentration of methanol at equilibrium, given the concentration of the reactants.
The equilibrium-constant expression is a mathematical equation that can be rearranged to solve for any of the variables in it. Rearrange the equilibrium-constant expression to solve for [CH3OH].
Kc[CO][H2]^2
Suppose that the molar concentrations for CO and H2 at equilibrium are [CO] = 0.02 M and [H2] = 0.06 M.
Use the formula you found in Part B to calculate the concentration of CH3OH.
Express your answer to one decimal place and include the appropriate units.
Answer:
[CH3OH(g)] = 1.7 M
Explanation:
CO(g) + 2H2(g) ↔ CH3OH(g)∴ Kc(25°C) = 2.3 E4 = [CH3OH(g)] / [CO(g)]×[H2(g)]²
⇒ [CH3OH(g)] = Kc.[CO(g)][H2(g)]²
∴ [CO(g)] = 0.02 M
∴ [H2(g)] = 0.06 M
⇒ [CH3OH(g)] = (2.3 E4)(0.02)(0.06)²
⇒ [CH3OH(g)] = 1.7 M
Final answer:
To find the equilibrium concentration of methanol, the equilibrium-constant expression is rearranged and the given concentrations of reactants are plugged in, yielding an equilibrium concentration of methanol equal to 1.7 M.
Explanation:
To calculate the equilibrium concentration of methanol ([tex]CH_3OH[/tex]) using the equilibrium constant (Kc), we start by writing the equilibrium-constant expression for the reaction:
Kc = [[tex]CH_3OH[/tex]] / ([[tex]CO][H_2]_2[/tex])
Given that Kc = 2.3 × 104, [CO] = 0.02 M, and [[tex]H_2[/tex]] = 0.06 M, we can rearrange the expression to solve for [[tex]CH_3OH[/tex]]:
[[tex]CH_3OH[/tex]] = Kc × [CO] × [tex][H_2]_2[/tex]
Plug in the values:
[[tex]CH_3OH[/tex]] = 2.3 × 104 × 0.02 M × (0.06 M)2
Calculating the above expression gives us:
[[tex]CH_3OH[/tex]] = 2.3 × 104 × 0.02 × 0.0036 = 1.656 M
Rounding to one decimal place, the equilibrium concentration of methanol is 1.7 M.
For a molecule with the formula AB2, the molecular shape is ________. For a molecule with the formula AB2, the molecular shape is ________. linear or T-shaped trigonal planar linear or bent linear or trigonal planar T-shaped
Final answer:
For a molecule with the formula AB2, if there are no lone pairs on the central atom, the molecular shape is linear, as in BeH2 or CO2. If one lone pair exists, it creates a bent or V-shaped structure, seen in molecules like SO2. Other geometries like trigonal planar or T-shaped are not possible for AB2.
Explanation:
For a molecule with the formula AB2, there are potentially different shapes that the molecule can have, depending on the presence and arrangement of lone pairs of electrons on the central atom. If there are no lone pairs on the central atom, the molecule would have a linear shape, with the two B atoms and the A atom arranged in a straight line. This can be seen in examples like BeH2 and CO2, where the central atom contains only two electron groups, and they orient themselves as far apart as possible—180° apart.
However, if there is one lone pair on the central atom, the shape will be bent, or V-shaped. This is because the molecule can be thought of as a trigonal planar structure with one vertex missing due to the lone pair. The lone pair takes up additional space, causing the bond angle to be less than 120°, as seen in molecules like SO2.
Lastly, with additional lone pairs, other geometries like trigonal planar can be eliminated. The molecule AB2 could also not exhibit a T-shaped geometry as that would require more than three electron groups on the central atom.
Consider the following reaction to generate hydrogen gas: Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g) The hydrogen gas is collected by displacement of water at 35.0 °C at a total pressure of 745 torr. The vapor pressure of water at 35.0 °C is 42 torr. Calculate the partial pressure of H2 (in atm) if 353.2 mL of gas is collected over water from this method.
Answer:
0.925 atm
Explanation:
By Dalton's Law, the total pressure of a gas mixture is the sum of the partial pressure of its components. The vapor pressure of the water is the pressure that some molecules that evaporated do under the liquid surface. The gas and the liquid are at equilibrium. So, the gas mixture is water vapor and hydrogen gas.
Ptotal = Pwater + PH₂
745 = 42 + PH₂
PH₂ = 703 torr
Transforming to atm:
1 atm ------------------760 torr
x ------------------ 703 torr
By a simple direct three rule
760x = 703
x = 0.925 atm
Le Chatelier's principle describes the effect of changing conditions on a chemical reaction that was previously at equilibrium. Choose the statement that correctly describes the possible effects.A. Adding more carbon dioxide to a combustion reaction will increase the rate of the reaction.B.When oxygen is removed from a combustion reaction, the reaction slows down or stops.C.When water is added to a combustion reaction, it will increase the rate of the reaction.
Answer:
.B.When oxygen is removed from a combustion reaction, the reaction slows down or stops.
Explanation:
Le Chatelier's principle -
The direction of the reaction by changing the concentration can be determined by Le Chatelier's principle,
It states that ,
When a reaction is at equilibrium , Changing the concentration , pressure, temperature disturbs the equilibrium , and the reaction again tries to attain equilibrium by counteracting the change.
The combustion reaction of carbon dioxide is as follows -
C + O₂ → CO₂
Hence ,
Removing O₂ from the system , i.e. decreasing the concentration of O₂ , according to Le Chatelier , the reaction will move in backward direction , to increase the amount of reduced O₂ .
Hence, reaction will go in backward direction.
The statement that correctly describes the possible effects of changing conditions on a chemical reaction is (B) When oxygen is removed from a combustion reaction, the reaction slows down or stops.
Le Chatelier's principle states that when a system at equilibrium experiences a change in concentration, temperature, or pressure, the equilibrium will shift to counteract the imposed change and restore a new equilibrium. If we consider a combustion reaction at equilibrium, we can apply Le Chatelier's principle to predict the effects of changing conditions:
Adding more carbon dioxide to a combustion reaction does not necessarily increase the rate of the reaction; instead, the equilibrium might adjust to offset the change.Removing oxygen from a combustion reaction generally causes the reaction to slow down or stop because the system will try to counteract the loss of a reactant by reducing the rate of the forward reaction.Adding water to a combustion reaction is unlikely to increase the rate of the reaction, and it might not be relevant unless water is a reactant or product in the equilibrium.Overall, according to Le Chatelier's principle, the system will adjust to a change by shifting the equilibrium position to either increase the concentration of reactants or products, depending on the direction of the change.
A 23.0 g piece of metal at 99.0 ∘C is placed in a calorimeter containing 53.2 g of water at 24.0 ∘C. The final temperature of the mixture is 26.1 ∘C. What is the specific heat capacity of the metal? Assume no energy is lost to the surroundings.
Answer: The specific heat of the metal is 0.277 J/g.ºC.
Explanation:
The specific heat (s) of a substance is the amount of heat required to raise the temperature of one gram of the substance by one degree Celsius. Its units are J/g.ºC.
If we know the specific heat and the amount of a substance, then the change in the sample’s temperature (ΔT) will tell us the amount of heat (q) that has been absorbed or released in a particular process. The equation for calculating the heat change is given by:
[tex]: q=m.s.ΔT[/tex]
Where ΔT is the temperature change: [tex]ΔT= tfinal - tinitial[/tex], m the mass and s the specific heat.
If no energy is lost to the sorroundings, then all the heat lost by the metal will be absorbed by the water. Therefore, the heat change of the system (qsystem) must be zero and we can write:
[tex]qsystem = qwater + qmetal[/tex]
[tex]qwater = -qmetal[/tex]
Replacing each term with the equation for calculating heat change:
[tex]mw.sw.ΔTw = -[mm.sm.ΔTm ][/tex]
A recommendation is to carry the units through the entire sequence of calculations. Therefore, if the equation is set up correctly, then all the units will cancel except the desired one.
[tex]53.2 g . 4.184 J/g°C . (26.1 - 24.0)ºC = -[23.0 g . sm . (26.1 - 99.0)°C][/tex]
[tex]464.436 J = -[23.0 g . sm . (-72.9)°C][/tex]
[tex]sm = 464.436 J/ -[-1676.7 g°C][/tex]
[tex]sm = 0.277 J/g.°C[/tex]
Thus, the specific heat of the metal is 0.277 J/g.ºC.
A sample of pure solid naphthalene (C10H8) weighing 0.6410 g is burned completely with oxygen to CO2(g) and H2O(,) in a constant-volume calorimeter at 25°C. The amount of heat evolved is observed to be 25.79 kJ.
Write and balance the chemical equation for the combustion reaction.
Answer: C10H8 + 12O2 ----> 10CO2 + 4H2O
Explanation:
To balance this, we have to make sure that the same number of atoms exist at both sides (Conservation of energy)
Note:The reaction is exothermic, giving off heat energy.
Left hand side: C= 10,
H=8,
O= 2×12=24
Right hand side: C= 10×1=10,
H= 4×2=8,
O=10×2=20 (for 10CO2) and 4×1=4 (All equal to 24)
With the above analysis, it is clear that numbers had to be added to molecules to get an equal number of atoms for both sides.
About one hundred thousand years ago, very fluid lava started erupting slowly and gently from a place near a plate boundary. What best describes the slope of the mountain that resulted from such a phenomenon?
Answer:
Steep slope with high mountain, as these are formed by a composite volcano
Explanation:
Answer:
Steep slope with high mountain, as these are formed by a composite volcano
Explanation:
Metallic and nonmetallic mineral resources are considered nonrenewable because Choose one:
A. natural processes make minerals much more slowly than we can mine them.
B. not every country has deposits of all the mineral resources it needs.
C. ore deposits are so rare.
D. reserves of mineral resources do not increase
Metallic and nonmetallic mineral resources are considered nonrenewable because natural processes make minerals much more slowly than we can mine them. Therefore, the correct option is option A.
What are non renewable resources?Natural resources that cannot be easily replenished by natural processes at a rate rapid enough even to keep up with use are considered non-renewable resources. Fossil fuels made of carbon are one instance. With the use of temperature and pressure, the original biological substance transforms into a fuel like gas or oil.
On the other hand, resources like lumber and wind are seen as renewable resources, primarily since their localized replenishment may take place during times that are also significant to people. Metallic and nonmetallic mineral resources are considered nonrenewable because natural processes make minerals much more slowly than we can mine them.
Therefore, the correct option is option A.
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A 0.04328 g sample of gas occupies 10.0-mL at 294.0 K and 1.10 atm. Upon further analysis, the compound is found to be 25.305% C and 74.695% Cl. What is the molecular formula of the compound?
Draw the Lewis structure of the compound. Identify the geometry around each carbon atom.
The molecular formula of the gas compound given is approximately CCl3. The geometry surrounding each carbon atom would be trigonal planar with each carbon being surrounded by three chlorine atoms. This can be determined using the given mass, ideal gas laws, and the percent composition of the constituents.
Explanation:The data given can be used alongside the Ideal Gas Law (PV=nRT) to find the molar mass of the gas. This molar mass, along with the percent composition of carbon (C) and chlorine (Cl), can be used to deduce the molecular formula of the compound.
The molar mass of chlorine is around 35.45 g/mol and for carbon, it's approximately 12.01 g/mol. With 25.305% C and 74.695%, the molecular formula becomes approximately CCl3, such that each carbon atom in the structure is surrounded by 3 chlorine atoms.
This geometry surrounding the carbon atom is trigonal planar based on VESPR theory. The Lewis structure would illustrate this with a carbon in the center surrounded evenly by three chlorine atoms.
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Magnesium hydroxide, the active ingredient in milk of magnesia, neutralizes stomach acid, primarily HCl, according to the reaction Mg(OH)2(aq) + 2HCl(aq) → 2H2O(l) + MgCl2(aq) How much HCl in grams can be neutralized by 5.50 g of Mg(OH)2?
Answer:
6.935g
Explanation:
From the question above, we can see that 1 mole of magnesium hydroxide neutralized 2 moles of hydrochloric acid.
Now, let's calculate the actual number of moles of magnesium hydroxide reacted. We can do this by dividing the mass of the magnesium hydroxide by the molar mass. Molar mass of the magnesium hydroxide is 24 + 2(17) = 58g/mol
The number of moles thus produced is 5.5/58 = 0.095moles
From the first relation we established that 1 mole of magnesium hydroxide reacted with 2 moles of hydrochloric acid. Hence, 0.095moles of magnesium hydroxide will yield 2 × 0.095 moles of hydrochloric acid = 0.190 moles
We then calculate the mass of HCl that be neutralized by multiplying the number of moles by the molar mass. The molar mass of HCl is 1 + 35.5 = 36.5g/mol.
The mass of HCl neutralized = 36.5 × 0.190 = 6.935g
Answer: The mass of [tex]HCl[/tex] neutralized can be, 6.88 grams.
Explanation : Given,
Mass of [tex]Mg(OH)_2[/tex] = 5.50 g
Molar mass of [tex]Mg(OH)_2[/tex] = 58.3 g/mol
Molar mass of [tex]HCl[/tex] = 36.5 g/mol
First we have to calculate the moles of [tex]Mg(OH)_2[/tex]
[tex]\text{Moles of }Mg(OH)_2=\frac{\text{Given mass }Mg(OH)_2}{\text{Molar mass }Mg(OH)_2}[/tex]
[tex]\text{Moles of }Mg(OH)_2=\frac{5.50g}{58.3g/mol}=0.0943mol[/tex]
Now we have to calculate the moles of [tex]HCl[/tex]
The balanced chemical equation is:
[tex]Mg(OH)_2(aq)+2HCl(aq)\rightarrow 2H_2O(l)+MgCl_2(aq)[/tex]
From the balanced reaction we conclude that
As, 1 mole of [tex]Mg(OH)_2[/tex] react with 2 mole of [tex]HCl[/tex]
So, 0.0943 moles of [tex]Mg(OH)_2[/tex] react with [tex]0.0943\times 2=0.1886[/tex] moles of [tex]HCl[/tex]
Now we have to calculate the mass of [tex]HCl[/tex]
[tex]\text{ Mass of }HCl=\text{ Moles of }HCl\times \text{ Molar mass of }HCl[/tex]
[tex]\text{ Mass of }HCl=(0.1886moles)\times (36.5g/mole)=6.88g[/tex]
Therefore, the mass of [tex]HCl[/tex] neutralized can be, 6.88 grams.
Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid. true or false
Answer:
The given statement is true.
Explanation:
Chlorine gas is prepared by heating manganese dioxide with hydrochloric acid.T he reaction takes place in two steps
1) Reaction between manganese dioxide and HCl gives manganese(II) chloride along with water and nascent oxygen.
[tex]MnO_2+2HCl\rightarrow MnCl_2+H_2O+O[/tex]...[1]
2) Then this nascent oxygen formed in above reaction oxidizes HCl into water and chlorine gas.
[tex]2HCl+O\rightarrow Cl_2+H_2O[/tex]..[2]
So , the net chemical reaction comes out to be:
[tex]MnO_2+4HCl\rightarrow MnCl_2+H_2O+Cl_2[/tex]
In the diagram, the black line represents the concentration of a reactant and the green line represents the concentration of a product.
Which statement best describes the reaction rate?
A. The product maintains an constant concentration in the first half of the reaction.
B. At the end of the reaction, both product and reactants are of a constant concentration.
C. The reactants maintain an constant concentration in the first half of the reaction.
D. At the end of the reaction, both product and reactants are of an equal concentration.
I think is A. Please correct me if I am wrong. Thank you!
Answer:
B. At the end of the reaction, both product and reactants are of a constant concentration.
Explanation:
Option A and C are similar as they both refer to constant concentration of product and reactant respectively in first half. As in the graph, the concentration of reactant and product changes (concentration of reactant decreases and concentration of product increase) with time in the first half[tex]^{*}[/tex] of the reaction. This made both A and C option wrong.Option D is also wrong as at the end of reaction[tex]^{**}[/tex] the line of concentration of product and reactant do not coincide which means they are not equal.Option B is correct as we take the end of reaction at the point where the concentration of reactant and product won't change much or become constant[tex]^{*}[/tex]first half time is the when concentration of reactant reduces to 50% of initial concentration which you can nearly assume on or before the point of intersection of both the concentration graphs.
[tex]^{**}[/tex]end of reaction is the time when the reaction completes which is theoretically infinite but generally we take end of the reaction as the time when the slope of concentration curve becomes nearly zero or the time when change in concentration of reactant and product is negligible.
Answer:
B. At the end of the reaction, both product and reactants are of a constant concentration.
Explanation:
Got it right on the test!
mastering chemistry hat do you predict for the height of a barometer column based on 1-iodododecane, when the atmospheric pressure is 751 torr ? Note that 1 torr corresponds to 1 mm of a liquid mercury column.
Answer:
the height of a iodododecane barometer column =66.46mm
Explanation:
we will the density of liquid 1-iodododecane and the density of mecury (compare with the given value of mercury)
when the atmospheric pressure is 751 torr ?
the compound 1-iodododecane has a density of 1.2g/mL
the density of mercury is 13.56g/mL
for mercury at
1 torr corresponds to 1 mm of a liquid mercury column= 13.56g/ml
for 1-iodododecane
751toor = ? at 1.2g/mL
1 torr = 1mm = 13.56
751 torr of mercury = 751mm = 13.56
751 toor of iodo = ? = 1.2
751mm = 13.56
? ====1.2
1.2 * 751)/13.56 =66.46mm
the height of a iodododecane barometer column =66.46mm
The height of a barometer column with 1-iodododecane at 751 torr would depend on the density of 1-iodododecane relative to mercury. Using the hydrostatic pressure formula, the height can be determined with the known density of 1-iodododecane.
Explanation:When considering the height of a barometer column based on 1-iodododecane at an atmospheric pressure of 751 torr, it's important to account for the density of 1-iodododecane relative to that of mercury. Since the density of the 1-iodododecane will be different from mercury (13.6 g/cm³), the height of the barometer column for the same atmospheric pressure would also be different. To find the height, one would need to use the formula for hydrostatic pressure, p = ρgh, where ρ is the density of the fluid, g is the acceleration due to gravity, and h is the height of the column. With the density of 1-iodododecane known, one could rearrange the formula to solve for h to find the expected height of the barometer column at 751 torr.
In a solution, the solvent In a solution, the solvent can be a liquid or gas. A. is the substance present in the smallest concentration. B. can be a solid, liquid, or gas. C. is a liquid. D. is never a solid.
Answer:
Can either be a solid, a liquid or a gas
Explanation:
A solvent can either be a solid, liquid or a gas. It is the carrier medium in a solution. It is the one in which the solute is dissolved.
Although quite unusual, a solvent might also be a solid. An important application of this can be seen in the production of alloys. Alloys are mixture of metals. To produce let’s say an alloy containing just two metals, the use of a solid solvent is needed. Here, one of the two metals is known as the base metal. It is this base metal that will serve as the carrier medium for the other metal
Ask Your Teacher Calculate the freezing-point depression and osmotic pressure in torr at 25°C for an aqueous solution of 3.2 g/L of a protein (molar mass = 9.0 ✕ 104 g/mol) if the density of the solution is 1.0 g/cm3
Answer:
Osmotic pressure(π) = 0.661 Torr.
Depression in freezing point = 6.64 * 10⁻⁵ °C.
Explanation:
To calculate depression in freezing point and osmotic pressure, let's start by calculating Molarity of the solution.
Also, protein undergoes no dissociation or association when in solution.
Molarity = [tex]\frac{Moles of solute}{liters of solution}[/tex]
Molarity = [tex]\frac{3.2 g/L}{9.0 * 10^{4}g/mol }[/tex]
Molarity= 3.56 * 10⁻⁵ mol/L
Temperature = 25 +273 = 298 K
Osmotic pressure(π) = M R T
= (3.56 * 10⁻⁵ mol/L)* (0.08206 L atm/ mol K) * (298 K)
= 87.055 * 10⁻⁵ atm
But 1 atm= 760 Torr
So, Osmotic pressure(π) = (87.055 * 10⁻⁵ atm) * ( 760 torr/ 1atm)
= 0.661 Torr.
The depression in freezing point Δ[tex]T_{f} =K_{f} * m[/tex]
[tex]K_{f}[/tex]= molal freezing point depression constant of the solvent (1.86 °C/m for water).
m= molality or molal concentration of the solution.
m= moles of solute in 1kg of solvent.
Density of solution = [tex]1.0 \frac{g}{cm^{3} }[/tex]
Mass of 1L(1000 cm³) of this solution is= density * volume of solution
= 1000g
Molarity means 3.56 * 10⁻⁵ mol of protein in 1L of solution
Mass of protein= 3.56 * 10⁻⁵ * 9.0 * 10⁴ = 3.2 g of protein
1000g of solution- 3.2 g of protein = 996.8 g of solvent
Molality = [tex]\frac{3.56 * 10⁻⁵ mol}{0.9968 kg}[/tex]
=3.57 * 10⁻⁵ m
depression in freezing point Δ[tex]T_{f} =K_{f} * m[/tex]
= 1.86 * 3.57 * 10⁻⁵ = 6.64 * 10⁻⁵ °C.
How does removing trees affect nitrogen cycling in a forest ecosystem?
Answer:
Deforestation can directly affect the nitrogen cycle within a forest ecosystem. It is because the nitrogen is used by the micro-organisms such as nitrogen fixing bacteria that helps in converting the atmospheric nitrogen into useful ammonia that are taken up by the plants, in order to carry out the process of photosynthesis.
By cutting down the trees and plants, these cycling of nitrogen will be disturbed and also these nitrogen containing articles will be eroded and eventually will mix up with the rivers and stream affecting the aquatic ecosystem.
Thus, by cutting down the trees, the nitrogen cycle will be disrupted in a forest ecosystem.
(A chemist burns one mole of C2H6 in oxygen and measures that 382 kJ of energy is released. How many grams of C2H6 must burn to raise the temperature of 39.0 L of water by 58.0°C? Assume the density of water to be 1.00 g/cm3.
Answer:
744.2 g of C2H6 must burn to raise the temperature of 39.0 L of water by 58.0°C
Explanation:
This excersise is about calorimetry.
Q = m . C . ΔT
For water, 58°C is the ΔT, and the specific heat is 4.18 kJ/kg°C. We are missing the mass, but with the density data, we can know it.
Water density = water mass / water volume
1 g/ml = water mass / 39000 mL
(Notice we had to convert 39 L in mL (.1000))
Water mass = 39000 g
But this is in grams, and we have to make again a conversion, to kg because the units of specific heat.
Q = 39 kg . 4.18 kJ/ kg.°C . 58°C
Q = 9455.16 kJ
This is the heat required to change water temperature with that water mass, and the heat released for one mol of C2H6 is 382kJ.
How many mol of C2H6, for the heat required to change water, need the chemist?. The rule of three will be:
382 kJ ____ 1 mol of C2H6
9455.16 kJ _____ (9455.16 / 382) = 24.7 moles of C2H6
For mass, just work with the molar weight.
Mol . molar weight = mass
24.7 mol . 30.07g/m =744.2 g
To raise the temperature of 39.0 L of water by 58.0°C, you will need to burn 756.504 grams of C2H6.
Explanation:Step 1: Convert the given volume of water to gramsGiven: 39.0 L of water; Density = 1.00 g/cm3
Mass = Volume x Density
Mass = 39.0 L x 1.00 g/cm3
Mass = 39.0 kg
Step 2: Calculate the heat required to raise the temperature of the waterHeat = Mass x Specific Heat x Temperature Change
Heat = 39.0 kg x 4.184 J/g °C x 58.0 °C
Heat = 9619.4 kJ
Step 3: Use the energy released in the combustion reaction to find the mass of C2H6Energy Released = 382 kJ
According to the balanced chemical equation, 1 mole of C2H6 releases 382 kJ
Therefore, we need to calculate the number of moles of C2H6 present in 382 kJ using the molar enthalpy change.
1 mole of C2H6 = 382 kJ
x moles of C2H6 = 9619.4 kJ
x = 9619.4 kJ * (1 mole of C2H6/382 kJ)
x = 25.2 moles of C2H6
Step 4: Convert moles of C2H6 to gramsMolar mass of C2H6 = 30.07 g/mol
Mass of C2H6 = Moles x Molar Mass
Mass of C2H6 = 25.2 moles x 30.07 g/mol
Mass of C2H6 = 756.504 g
Therefore, 756.504 grams of C2H6 must burn to raise the temperature of 39.0 L of water by 58.0°C.
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Which of the following processes have a ΔS > 0? A. N2(g) + 3 H2(g) → 2 NH3(g) B. Na2CO3(s) + H2O(g) + CO2(g) → 2 NaHCO3(s) C. CH3OH(l) → CH3OH(s) D. All of these processes have a ΔS > 0. E. CH4(g) + H2O (g) → CO(g) + 3 H2(g)
Answer:
ΔS > 0 only for choice E: CH4(g) + H2O (g) → CO(g) + 3 H2(g)
Explanation:
Our strategy in this question is to use the trend in entropies :
S (solids) less than S (liquids) less than S (gases)
Also we have to look for the molar quanties involved of each state and their change to answer the question:
A. N2(g) + 3 H2(g) → 2 NH3(g)
Here we have 4 moles gases going to 2 moles of products, so the change in entropy is negative.
B. Na2CO3(s) + H2O(g) + CO2(g) → 2 NaHCO3(s)
The change in entropy is negative since we have 2 mol gases in the reactants and zero in the products.
C. CH3OH(l) → CH3OH(s)
A liquid has a higher entropy than a solid so ΔS is negative
D. False see A,B,C
E. The change in moles of gases is 4 - 2= 2, therefore ΔS is greater than O.
The reaction CH4(g) + H2O (g) → CO(g) + 3 H2(g) will have ΔS > 0.
The term entropy refers to the degree of disorder of a system. Hence, the change in entropy is positive (greater than zero) when there is an increase in the degree of disorderliness of the system.
As such, the reaction;
CH4(g) + H2O (g) → CO(g) + 3 H2(g)will experience an increase in entropy since there is an increase in the number of molecules of gaseous species from left to right.
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When Adams blank blank or blank electrons an attract forms between the blank pulling them together to form a blank the attraction is called a blank a chemical bond is the blank that blank
Most chemical reactions involve the evolution or absorption of heat energy. True or False
Answer:
True
Explanation:
The majority of the reactions happened with a flow of heat. When there's no heat, the reaction is adiabatic.
For no adiabatic reactions, the heat can be released (evolution) by the system, so the reaction will be exothermic, or absorbed by the system (absorption), then the reaction is called endothermic.
A spectrophotometer measures the transmittance or the absorbance, or both, of a particular wavelength of light after it has passed through a liquid sample. Before the transmittance or absorbance of the sample is measured, a cuvette filled only with solvent, called the blank, is placed in the spectrophotometer and measured. Select the reason that, after the blank is measured, the cuvette must be placed in the spectrophotometer in the same orientation each time that it is used.
a. The spectrophotometer will break if the cuvette position is changed during the experiment.
b. The transmittance of the cuvette must be measured in the same place each time.
c. The cuvette will only fit into the spectrophotometer in one orientation.
d. The transmittance of the liquid must be measured in the same place each time.
Answer:
b. The transmittance of the cuvette must be measured in the same place each time.
Explanation:
When using a spectrophotometer, light passes not only through the liquid sample, it also passes through the cuvette. This means that each time a reading is made, you not only measure the transmittance/absorbance of the sample, but of the cuvette as well.
For this reason it's important that the reading of the cuvette's absorbance remains the same through all the process, so the answer is b), because different faces of the cuvette may have different absorbances.
‘A’ is an element which belongs to period 3, having 6 electrons in its valence shell. Below is a list of successive ionization energies (in kJ/mol) for period 3. IE2 = 2250 IE3 = 3360 IE4 = 4560 IE5 = 7010 IE6 = 8500 IE7 = 27,100 Identify the element ‘A’
Answer:
The element A is S (sulfur)
Explanation:
The elements for the 3erd period in the periodic table are Na, Mg, Al, Si, P, S, Cl and Ar.
The one that has 6 e⁻ in its valence shell is the S, because it is missing 2 e⁻ to reach the octet rule. 2 e⁻ to has the most stable noble gas conformation.
The IE of S = 3360 kJ/mol
It is a little lower than Cl because the electron is so far from the nucleus, that's why we have to apply a very low ionization energy to rip the electron off.
The element 'A' in question, which belongs to period 3 and has 6 valence electrons, is most likely aluminum (Al).
Explanation:Based on the given information, the element 'A' belongs to period 3 and has 6 valence electrons. To identify the element, we need to find the ionization energy values that match the given pattern. Looking at the successive ionization energies provided, we can see that the jump in ionization energy occurs after the third ionization. Since 'A' has 6 valence electrons, it is likely to be aluminum (Al), which fits the pattern.
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The halogens form a series of compounds with each other, which are called interhalogens. Examples are bromine chloride (BrCl), iodine bromide (IBr), bromine fluoride (BrF), and chlorine fluoride (ClF). Which is expected to have the lowest boiling point?
Final answer:
The interhalogen with the lowest boiling point is bromine chloride (BrCl) because both bromine and chlorine are smaller atoms compared to iodine.
Explanation:
The boiling point of a compound is determined by the strength of the intermolecular forces between its molecules. In the case of the interhalogens, the boiling point generally increases as the size and atomic mass of the halogen atoms increase. Therefore, the interhalogen with the lowest boiling point would be the one with the smallest halogen atom.
Among the given examples, bromine chloride (BrCl) has the lowest boiling point because both bromine and chlorine are smaller atoms compared to iodine. Iodine bromide (IBr) would have a higher boiling point since iodine is larger than both bromine and chlorine.
Similarly, bromine fluoride (BrF) would have a higher boiling point compared to bromine chloride due to the presence of a larger fluorine atom. Lastly, chlorine fluoride (ClF) would have the highest boiling point because both chlorine and fluorine are smaller atoms compared to bromine.
Fe(s) + CuSO4(aq) ⇒ Cu(s) + FeSO4(aq)
Which reactant is a substance that is dissolved in solution?
Answer:
The answer to your question is CuSO₄
Explanation:
To answer your question just remember the following information
- A chemical reaction is divided into sections
reactants and products
reactants on the left side of the reaction
products on the right side of the reaction
- All the symbols have a meaning
(s) means that that compound is in solid phase
(aq) means that that compound is dissolved in solution.
Then, the answer is CuSO₄
A particular solvent with ΔS∘vap=112.9J/(K⋅mol) and ΔH∘vap=38.0kJ/mol is being considered for an experiment. In the experiment, which is to be run at 75 ∘C, the solvent must not boil. Based on the overall entropy change associated with the vaporization reaction, would this solvent be suitable and why or why not?
Answer:
This solvent is not suitable because ΔS°vap > 0.
Explanation:
Let's consider a system at a higher temperature T1, and its surroundings at a lower temperature T2. Let's call q the heat that goes irreversible from the system to the surroundings:
ΔSsystem = -q/T1 (it's losing heat, so q must be negative)
ΔSsurroundings= q/T2
ΔSprocess = ΔSsystem + ΔSsurroundings
ΔSprocess = -q/T1 + q/T2
ΔSprocess = q*(1/T2 - 1/T1)
ΔSprocess = q*[(T1 - T2)/(T1*T2)]
As pointed above, T1> T2, so ΔSprocess > 0 and because of that, the reaction is spontaneous. It means that if ΔS°vap > 0, the solvent will vaporize. So, as we can notice, the solvent given is not suitable.
Final answer:
The overall entropy change for vaporization helps determine if a solvent is suitable for an experiment. A high value of entropy indicates increased disorder, making vaporization likely. In this case, with a high entropy of 112.9 J/(K⋅mol), the solvent's boiling at 75 ∘C may hinder its suitability for the experiment.
Explanation:
The overall entropy change associated with the vaporization reaction can be calculated considering the entropy of vaporization (ΔSvap) and the enthalpy of vaporization (ΔHvap) of the solvent. As stated in Trouton's rule, ΔSvap is approximately 10.5R, which is around 85-88 J/(mol K) for many liquids. In this case, with a ΔSvap of 112.9 J/(K⋅mol) and a ΔHvap of 38.0 kJ/mol, the high ΔSvap value indicates that the solvent has a highly disordered structure, making it likely to vaporize at the given temperature of 75 ∘C, hence making it unsuitable for the experiment.
Do a graphical analysis of data provided from an example experiment.
My hypothesis was that if the ice is heated to 3 degrees Celsius or above it will fully melt into water. If the water continues to be heated and reaches 100 degrees Celsius or above, then it will boil. My hypothesis was partially correct. The water fully melted at 1 degree Celsius and not at 3 degrees as I had predicted but did in fact boil at 100 degrees Celsius.
Answer:
its B
Explanation: