Answer:
8,860 J = 8.86 kJExplanation:
The heat energy required to heat a substance may be calculated from the formula:
Q = m × C × ΔTWhere:
m = mass of substance = 123.00 kg of waterC = specific heat = 1 J⁻¹ kg K⁻¹ΔT increase of temperature = 97°C - 25°C = 72°C = 72 K.Then, substitute the numbers in the formula to get:
Q = 123.00 kg × 1 J⁻¹ kg K⁻¹ × 72 K = 8,856 J ≈ 8,860 J or 8.86 kJIn free fall, all objects fall with the same acceleration.
O
A. True
O
B. False
Answer:
A. True
Explanation:
Objects that are said to be undergoing free fall, are not encountering a significant force of air resistance; they are falling under the sole influence of gravity. Under such conditions, all objects will fall with the same rate of acceleration, regardless of their mass
Answer:
true
Explanation:
weight and shape does not matte in a perfect world unfortunately they are effected in our world where there is friction and air resistance
what is h20????????????????????
Answer:
H2O is the chemical formula for water or in simple language its is water
Explanation:
Water, one of the most vital elements for life on Earth, has the chemical formula [tex]H_20[/tex]. It is made up of one oxygen atom and two hydrogen atoms joined together covalently.
Due to its polar nature, water can establish hydrogen bonds with other molecules, giving it special features including high surface tension, cohesiveness, and thermal stability. It serves as a solvent, a medium for metabolic reactions, and a mechanism for controlling temperature, all of which are essential for diverse biological activities. Water is also essential to the functioning of Earth's ecosystems since it erodes the land and supports a variety of aquatic life. Water is essential for supporting all forms of life because of its quantity and adaptability.
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why is the structure of a molecule important to its function
Answer:
It determines how biological molecules recognize and respond to one another with specificity.
Explanation:
A molecule has a characteristic size and shape. The precise shape of a molecule is usually very important to its function in the living cell. Molecular shape is crucial in biology because it determines how biological molecules recognize and respond to one another with specificity.
Answer:
the structure of a molecule affects how it interacts with other molecules
Explanation:
I took the test
A mixture of three noble gases has a total pressure of 1.25 atm. The individual pressures exerted by neon and argon are 0.68
atm and 0.35 atm, respectively. What is the partial pressure of the third gas, helium?
Use Py=P+P 2+P3+ +Pm
First of all, as you seen the gases are noble which means that will not react with each other and in this case each gas create individual pressure.
P[tex]_{T}[/tex]= total pressure
P[tex]_{Ne}[/tex] = pressure of neon
P[tex]_{Ar}[/tex] = pressure of argon
P[tex]_{He}[/tex] = pressure of helium {which is required}
P[tex]_{T}[/tex] = P[tex]_{Ne}[/tex] + P[tex]_{Ar}[/tex] + P[tex]_{He}[/tex]
1.25 = 0.68 + 0.35 + P[tex]_{He}[/tex]
P[tex]_{He}[/tex] = 1.25 - [0.68 + 0.35] = 0.22 atm
What is the study of matter called?
O
A. Chemistry
O
B. Philosophy
O
O
C. Biology
D. Physics
Hello There!
The science of matter is called chemistry. Chemistry is the science of matter and its changes that occur. Everything in our universe is made up of matter and it has to have mass and take up space to be considered this.
The salt formed by the reaction of the weak acid hydrocyanic acid, HCN, with the strong base potassium hydroxide is
potassium cyanide, KCN. What is the hydroxide ion concentration of a 0.255 M solution of potassium cyanide at 25 °C
given that the value of for hydrocyanic acid is 4.9 X 10-102
Answer:
2.28 × 10^-3 mol/L
Explanation:
The equation for the equilibrium is
CN^- + H2O ⇌ HCN + OH^-
Ka = 4.9 × 10^-10
KaKb = Kw
4.9 × 10^-10 Kb = 1.00 × 10^-14
Kb = (1.00 × 10^-14)/(4.9 × 10^-10) = 2.05 × 10^-5
Now, we can set up an ICE table
CN^- + H2O ⇌ HCN + OH^-
I/(mol/L) 0.255 0 0
C/(mol/L) -x +x +x
E/(mol/L) 0.255 - x x x
Ka = x^2/(0.255 - x) = 2.05 × 10^-5
Check for negligibility
0.255/(2.05 × 10^-5) = 12 000 > 400. ∴ x ≪ 0.255
x^2 = 0.255(2.05 × 10^-5) = 5.20 × 10^-6
x = sqrt(5.20 × 10^-6) = 2.28 × 10^-3
[OH^-] = x mol/L = 2.28 × 10^-3 mol/L
What is the pH of a 3.5 × 10-11 M
H+ solution?
Answer:
10.45
Explanation:
pH = -log [H+]
pH = -log ( 3.5*10^-11)
pH = 10.45
Answer:
10.45
Explanation:
A 50°C solution has a pH of 3.30. At this temperature, Kw = 5.48 x 10 9. What is the pOH of the solution?
Answer:
9.93
Explanation:
Your value for Kw is incorrect. The correct value is 5.48 × 10^-14.
pH + pOH = pKw
3.30 + pOH = -log(5.84 × 10^-14) = 13.23
pOH = 13.23 - 3.30 = 9.93
The pOH of the solution is 9.93.
The pOH of the solution is 10 .
Given that, the pH of the solution is 3.30, we also know that;
pH = - log[H^+]
Hence;
[H^+] = Antilog (-3.3)
[H^+] = 5.0 × 10^-4 M
But;
Kw = [H^+] [OH^-]
[OH^-] = Kw/[H^+]
The accurate value of Kw is 5.48 × 10^-14 not 5.48 x 10 9
[OH^-] = 5.48 x 10^-14/ 5.0 × 10^-4
[OH^-] = 1.1 x 10^-10 M
pOH = - log[1.1 x 10^-10 M]
pOH = 10
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Consider the following unbalanced redox reaction:
Cr2O72- (aq) + NO2 (aq) – Cr3+ (aq) + NO3(aq)
What is the oxidizing agent in the reaction?
The oxidizing agent in the reaction Cr2O72- (aq) + NO2 (aq) – Cr3+ (aq) + NO3 (aq) is Cr2O72-, as it is reduced, meaning it accepts electrons, going from a chromium oxidation state of +6 to +3.
Explanation:In a redox reaction, the oxidizing agent is the substance that is reduced, meaning it gains electrons. In the unbalanced reaction: Cr2O72- (aq) + NO2 (aq) – Cr3+ (aq) + NO3(aq), the Cr2O72- ions are reduced to Cr3+ ions.
This is determined through the observation of the oxidation states of the substances before and after the reaction. The oxidation state of chromium in Cr2O72- is +6, while it is +3 in Cr3+. This reduction in oxidation state indicates that Cr2O72- accepted electrons, meaning it is the oxidizing agent in this reaction.
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Which of the following increases the chance of a reaction when two
molecules collide?
O
A. Increasing the concentration of the molecules
O
B. Increasing the activation energy of the reaction
O
C. Decreasing the temperature of the system
O
D. Slowing down the speed of the molecules
Answer:
C. Decreasing the temperature of the system.
Explanation:
Decreasing the temperature of the system increases the chance of a reaction when two molecules collide.
The chance of a reaction when two molecules collide is increased by 'Increasing the concentration of the molecules', while the other options listed ('increasing the activation energy of the reaction', 'decreasing the temperature of the system', 'slowing down the speed of the molecules') actually decrease the chance of a reaction.
Explanation:The chance of a reaction when two molecules collide can be increased via one or more of several methods, each corresponding to different options presented in your question. Option A. Increasing the concentration of the molecules, leads to more frequent collisions and thus a higher chance of reaction. Option B. Increasing the activation energy of the reaction, instead, makes reactions less likely because more energy is needed for the reaction to occur. Option C. Decreasing the temperature of the system also reduces the chance of reaction as it slows down molecular motion and thus collisions. Option D. Slowing down the speed of the molecules also decreases the chance of reactions as it reduces the frequency of collisions. Based on these considerations, only Option A. Increasing the concentration of the molecules increases the chance of a reaction when two molecules collide.
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What is a reaction rate?
Answer:
A reaction rate is a measure of how fast a reactant disappears or a product forms during a reaction.
Explanation:
It is usually defined as the change in concentration per unit time:
Δ(concentration)/Δt
The units are (moles per litre) per second.
In symbols, the units are mol/(L·s) or mol·L^-1 s^-1.
How many grams of PbBr2 will precipitate when excess CrBr; solution is added to 60.0 mL of 0.551 M Pb(NO3)2 solution?
3Pb(NO3)2(aq) + 2CrBr3(aq) –>3PbBrz(s) + 2Cr(NO3)(aq)
Answer:
5.48 g
Explanation:
M: 367.01
3Pb(NO3)2(aq) + 2CrBr3(aq) → 3PbBr2(s) + 2Cr(NO3)3(aq)
1. Moles of Pb(NO3)2
n = 30.0 mL × (0.551 mmol/1 mL) = 16.53 mmol Pb(NO3)2
2. Moles of PbBr2
n = 16.53 mmol Pb(NO3)2 × (3 mmol PbBr/3 mol Pb(NO3)2)
= 16.53 mmol PbBr2
(3) Mass of PbBr2 formed
m = 16.53 mmol × (367.01 mg/1 mol) = 6067 mg
(4) Mass of PbBr2 in solution
PbBr2 is slightly soluble, so a significant amount will remain in solution.
Its solubility is 973 mg/100 mL.
Mass of dissolved PbBr2 = 60.0 mL × 973 mg/100 mL = 584 mg
(5) Mass of precipitate
Mass of precipitate = mass of PbBr2 formed - mass of PbBr2 in solution
m = 6067 mg - 584 mg = 5480 mg = 5.48 g
The mass of precipitate is 5.48 g.
The mass of PbBr2 precipitate produced is 12.1 g.
The equation of the reaction is;
3Pb(NO3)2(aq) + 2CrBr3(aq) –>3PbBr2(s) + 2Cr(NO3)3(aq)
Number of moles of Pb(NO3)2 = 60.0/1000 L × 0.551 M = 0.0331 moles
From the information in the question, we already know that Pb(NO3)2 is the limiting reactant and CrBr3 is the reactant in excess.
From the equation of the reaction;
3 moles of Pb(NO3) yields 3 moles of PbBr2
0.0331 moles of Pb(NO3) yields 0.0331 moles × 3 moles/3 moles
= 0.0331 moles of PbBr2
Mass of PbBr2 = number of moles × molar mass
Mass of PbBr2 = 0.0331 moles × 367 g/mol= 12.1 g
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PLEASE.
Where are nonmetals located in the periodic table?
along the upper right side
along the bottom
along the upper left side
in the middle
Answer:
Along the upper right side
What is the total number of electrons that can occupy the f sub level
Answer:
14 Electrons
Explanation:
I know because I know
Answer:
14 electrons can occupy the f sub level
Explanation:
Electronic configuration is the short representation which we use to represent the structure of an atom.
Atomic number of phosphorus is 15 so it has 15 electrons.
The electronic configuration of Phosphorus is given as [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex]
Here the superscript number represents the electrons 2 + 2 + 6 + 2 + 3 = 15 electrons of Phosphorus
Orbital diagram too is used for this purpose.
A circle or a square is used to represent an orbital.
This is the orbital diagram of Radon (atomic number -86)
Each orbital occupies 2 electron.
Shells are named using letters K, L, M, N and so on or using numbers 1, 2, 3, 4 etc.,
The number of electrons, a shell can accommodate is found using formula [tex]2n^2[/tex] where n is the number of the shell.
Shell 1 contains subshell s
Shell 2 contains subshell s, p
Shell 3 contains subshell s, p, d
Shell 4 contains subshell s, p, d, f
Subshells or sub level are represented by letters s, p, d, f, g, h, i and so on.
s contains 1 orbital with 2 electrons
p subshell contains 3 orbital with 6 electrons
d with 5 orbitals and 10 electrons
f with 7 orbitals and 14 electrons.
(Answer)
What is heat vaporization?
A)it is the heat required to change a substance’s temp by 1degreeC.
B)it is the heat required to change a gram of substance from a solid to a liquid.
C)it is the heat required to change a substance from a solid directly to a gas.
D)It is the heat required to change a gram of substance from a liquid to a gas.
E)It is the heat required to separate one substance into two substances.
Hi!!
CORRECT ANSWER = D
Heat vaporization is
D- It's the heat required to change a gram of substance from a liquid to a gas
☺☺☺
You have 500 mL of 5 M HCI already made. You need to dilute the solution to 1 M HCI. How much water will you need to add?
a 2500 ml
062.01
CC 2.51
d 2.5 ml
Answer:
a. 2500 ml of water is needed
Explanation:
V1C1=V2C2
(500)(5)=(1)V2
2500/1=V2
2500 = v2
The Galilean moons are satellites of which planet? Jupiter Mars Saturn Uranus
Answer:
Jupiter
Explanation:
The Galilean moons of Jupiter are Io, Europa, Ganymede, and Callisto.
Answer:
Jupiter
Explanation:
The Galilean moons are the four largest moons of Jupiter, first found by Galileo Galilei in either December of 1609 or January of 1610. He recognized them are satellites in March of 1610.
Which solution is an example of a nonelectrolyte?
Potassium chloride is an electrolyte, fructose and isopropyl alcohol are nonelectrolytes, and magnesium hydroxide is an electrolyte.
Explanation:1. Potassium chloride is an ionic compound and when it dissolves in water, its ions separate, making it an electrolyte.
2. Fructose is a molecular compound, and when it dissolves in water, it does not produce ions. Therefore, it is a nonelectrolyte.
3. Isopropyl alcohol is an organic molecule and its bonding is all covalent. When isopropyl alcohol dissolves in water, it separates into individual molecules but not ions. Thus, it is a nonelectrolyte.
4. Magnesium hydroxide is an ionic compound, so when it dissolves, it dissociates into ions, making it an electrolyte.
how many moles of gas Does it take to occupy 520 mL at a pressure of 400 torr and a temperature of 340 k
A.73.6 moles
B. 0.0098 moles
C.0.980 moles
D. 0.0735 moles
Final answer:
To find how many moles of gas occupy a given volume under certain conditions, we use the ideal gas law PV = nRT with proper unit conversions. Upon calculation with the conditions provided (520 mL at 400 torr and 340 K), the result is approximately 0.0098 moles, which is option B.
Explanation:
To determine how many moles of gas occupy 520 mL at a pressure of 400 torr and a temperature of 340 K, we use the ideal gas law equation PV = nRT. To use this equation, we must first convert the volume of the gas from mL to L (since R, the gas constant, is given in liters), and the pressure from torr to atm because R is also defined with pressure in atmosphere. 1 atm = 760 torr, so 400 torr is equal to 400 torr / 760 torr/atm = 0.5263 atm. The volume is 520 mL, which is 0.520 L. The value of R (the gas constant) is 0.0821 L atm / (K mol).
Now we can plug values into the ideal gas law:
PV = nRT
(0.5263 atm) × (0.520 L) = n × (0.0821 L atm / (K mol)) × (340 K)
After calculation, we find:
(0.5263 atm × 0.520 L) / (0.0821 L atm / (K mol) × 340 K) = n
n ≈ 0.0098 moles
Therefore, the answer is (B) 0.0098 moles.
what is the weight of dark matter
Answer:
Knowing this, researchers from the University of Southern Denmark decided to investigate the size of these hypothetical hidden particles. According to the team, dark matter could weigh more than 10 billion billion (10^9) times more than a proton.
Explanation:
If this is true, a single dark matter particle could weigh about 1 microgram, which is about one-third the mass of a human cell (a typical human cell weighs about 3.5 micrograms), and right under the threshold for a particle to become a black hole.
Answer ASAP 50 pts
What sources of error may have contributed to the percent yield not being 100 percent? Think about things that may have led to inaccurate measurements or where mass of the product could have been lost if this experiment was conducted in a physical laboratory.
Percent yield is the ratio between actual and theoretical yield multiplied by 100%. The higher the actual yield the higher is the percent yield. In the percent yield there is always a limiting reagent that creates the difference between what is obtained and what is calculated. Percent yield can never exceed 100% if that happens it means that there was some error in the theoretical yield calculation.
What does the letter R symbolize in a structural formula, such as RCOOH?
Answer:
R means there's a number of carbon in the chain.
Explanation:
For example RCOOH means that after x number of carbon, the chain ends with COOH.
Answer:
The correct answer is "a radical formed by carbons".
Explanation:
Carboxylic acids are a group of compounds characterized by a functional group called the carboxyl group. In a structural formula of a carboxylic acid, such as RCOOH, R symbolizes the existence of a radical formed by a certain amount of carbons attached to the functional group called the carboxyl group (COOH).
Have a nice day!
Give the location of the elements found in the periodic table which have the same number valence electrons.
A. All members in group VIII only
B. All numbers within any group
C. All numbers within any period
D. All the nonmetals
Answer:
B - all numbers within any group (vertical column)
Explanation:
https://en.wikipedia.org/wiki/Valence_electron
Answer:
B - all numbers within any group
Explanation:
Which example best demonstrates Charles’s law?
A.
The volume of a hot air balloon increases as the air inside it is heated.
B.
The pressure inside a pressure cooker increases as the food inside is heated.
C.
A balloon filled with air expands as it rises in altitude.
D.
A syringe pulls in air as the plunger is pulled back.
Answer:
D. A syringe pulls in air as the plunger is pulled back.
Explanation:
As per Charles’s law
At constant pressure for a given amount of a gas,
Volume is directly proportional to its temperature.
Directly proportional means when one increases the other one too will increase. That is when volume increases temperature too will increase. When volume decreases, temperature too will show a decrease.
Option A tells us that the volume of the hot air balloon increase due to the rise(increase) in temperature as the balloon is heated
Thus the expression is [tex]V \propto T[/tex]
[tex]\frac {V}{T} = k[/tex] where k is a constant
When there is a change in the volume and temperature the expression will be
[tex]\frac {V_1}{T_1} = \frac {V_2}{T_2}[/tex]
where [tex]V_1[/tex] and [tex]T_1[/tex] are the initial volume and initial temperature and [tex]V_2[/tex] and [tex]T_2[/tex] are the final volume and temperature.
Final answer:
The best example of Charles's Law is the increase in the volume of a hot air balloon as the air inside it is heated. This demonstrates the direct proportionality between the volume of a gas and its temperature when pressure and the amount of gas are constant. So the correct option is A.
Explanation:
The question pertains to Charles's Law, which states that the volume of a gas is directly proportional to its temperature (in kelvins), provided the pressure and the amount of gas remain constant. The best demonstration of Charles's Law among the given options is 'The volume of a hot air balloon increases as the air inside it is heated.' This is because as the air inside the balloon is heated, its molecules increase in kinetic energy, which leads to an increase in volume, causing the balloon to expand.
Which of these statements best describes the formula unit for a compound made from Mg and Cl?
It is MgCl2 because the total negative charge on Cl is one.
It is Mg2Cl because the total negative charge on Mg is one.
It is MgCl2 because the total positive charge on Mg is two.
It is Mg2Cl because the total positive charge on Mg is two.
WILL MARK BRAINLIEST
Answer:
It is MgCl₂ because the total positive charge on Mg is two
Explanation:
The bond between the atoms that makes up the formula unit of the compound is an ionic bond. This bond involves the transfer of electrons between atoms.
Mg is in the second group on the period on the periodic table. It has two valence electrons and would readily lose it to have a stable atomic configuration like those of noble gases. This leaves magnesium with a net positive charge of 2. Each chlorine atom gains one electron to achieve their own octet.
The formula unit of a substance composed of magnesium (Mg) and chlorine (Cl) is [tex]MgCl_2.[/tex] Therefore, the correct option are C and D.
This is due to the fact that while chlorine has a negative charge of -1, magnesium has a positive charge of +2. Two chloride ions combine with one magnesium ion to equalize the charges and provide electrical neutrality.
The two chlorine ions combine to provide a total negative charge of -2 because each chlorine ion adds a charge of -1. The negative charge of the chlorine ions is balanced by the +2 charge of the magnesium ions. As a result, the molecule formed by the combination of one magnesium ion and two chlorine ions is represented by the formula unit [tex]MgCl_2[/tex].
Therefore, the correct option are C and D.
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Which is true of Saturn's satellite, Titan?
O
A. It is about half the size of the planet it orbits.
O
B. It is Saturn's only satellite.
C. Its surface temperature is much warmer than the surface
temperature of Earth.
D
D. It may be similar to Earth's early conditions.
Answer:
D. It may be similar to Earth's early conditions.
Explanation:
Titan is one of the many satellites orbiting planet saturn. This satellite is very interesting as it shows a lot of similarities with the conditions at play when the early earth formed.
The early earth atmosphere was made up of reduced gases lacking in oxygen. Titan's atmosphere also share this similarity. It's atmosphere is predominantly made up of nitrogen, methane and carbon dioxide.
Titan also has a rocky surface just like earth and it has an atmospheric cover.
Answer:
it may be similar to earths early conditions
Explanation:
Assume you add 5 g of Nacl to a beaker and add water until the volume of the solution reaches 4 L. Calculate the concentration of salt in water in g/L and mol/L.
Answer:
1.25 g/L.
0.0214 mol/L.
Explanation:
Concentration in g/L = 5/4
= 1.25 g/L (answer).
As for mol / L we need to know the molar mass of salt.
It is 22.99 + 35.45 = 58.44.
So in mol/L it is 1.25 / 58.44
= 0.0214 mol/L.
How does the reaction, A + BC ⇌ AB + C, differ from the reaction, N2 + 3H2 ⇌ 2NH3 + energy, by which ammonia is synthesized?
Answer:
N₂+3H₂ ⇄2NH₃ is a thermochemical reaction whereas A+BC⇄AB is not.
A+BC⇄AB is a reaction of pure a element with a compound while N₂+3H₂ ⇄2NH₃ is a reaction between two pure elements.
Explanation:
Let A+BC⇄AB be equation i and N₂+3H₂ ⇄2NH₃ be equation ii.
The two reactions differ in that ii is a thermo-chemical reaction whereas i is not. This is because energy is included in reaction ii but not included in reaction i.
Also i is a reaction of pure a element with a compound while ii is a reaction between two pure elements. The compound is BC while the pure element is A.
Answer:
A is a single displacement reaction; B is a combination (synthesis) reaction.
Explanation:
The first reaction
A + BC → AB + C
This is a single displacement reaction, in which an element A displaces another element C from its compound BC.
The second reaction
N2 + 3H2 → 2NH3
The coefficients don't matter in determining the type of reaction, so we can rewrite this equation as
A + B → AB
It then becomes more obvious that this is a combination (synthesis) reaction, in which two elements combine to form a compound.
why is concentrated sulphuric acid is weak acid
Answer:
Sulfuric acid is a strong acid in any state
Explanation:
You may be thinking if the definition that a weak acid produces relatively few ions in aqueous solution,
If you have 100 % sulfuric acid, there is no water, so the definition does not apply.
Commercial sulfuric acid contains about 2 % water. The sulfuric acid in that small amount of water consists of about 99 % HSO₄⁻ and 1 % SO₄²⁻. The acid is almost completely ionized.
Sulfuric acid is a strong acid.
• identify early ideas about evolution
Answer:
There are two ideas about evolution.
1.) Religious
2.) Scientific
In religion, people believe that we were created through god.
In the scientific, people believe that we were created from apes and that throughout the time we became humans.
Explanation:
Naturalists began to focus on the variability of species; the emergence of paleontology with the concept of extinction further undermined static views of nature. In the early 19th century Jean-Baptiste Lamarck (1744–1829) proposed his theory of the transmutation of species, the first fully formed theory of evolution.
In classical Latin, though, evolution had first denoted the unrolling of a scroll, and by the early 17th century, the English word evolution was often applied to 'the process of unrolling, opening out, or revealing'. It is this aspect of its application which may have been behind Darwin's reluctance to use the term.