Answer:
c = 4016.64 j/g.°C
Explanation:
Given data:
Mass of substance = 2.50 g
Calories release = 12 cal (12 ×4184 = 50208 j)
Initial temperature = 25°C
Final temperature = 20°C
Specific heat of substance = ?
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Solution:
Q = m.c. ΔT
ΔT = T2 - T1
ΔT = 20°C - 25°C
ΔT = -5°C
50208 j = 2.50 g . c. -5°C
50208 j = -12.5 g.°C .c
50208 j /-12.5 g.°C = c
c = 4016.64 j/g.°C
The specific heat of the substance is calculated using the formula [tex]Q = mc \Delta T[/tex], with given values of mass, heat, and temperature change. The result is a specific heat of 0.96 cal/g°C.
The specific heat is defined as the amount of heat per unit mass required to raise the temperature by one degree Celsius. The formula to calculate specific heat (c) when the heat (Q) is lost or gained is:
[tex]Q = mc \Delta T[/tex]
Where Q is heat in calories, m is mass in grams, c is specific heat in cal/g°C, and [tex]\Delta T[/tex] is the temperature change in Celsius.
Using the student's data:
Mass (m) = 2.50 g
Heat (Q) = -12 cal (negative because heat is released)
Temperature change ([tex]\Delta T[/tex]) = 20°C - 25°C = -5°C
Now, solving for c:
-12 cal = (2.50 g) c(-5°C)
c = -12 cal / (2.50 g imes -5°C)
c = 0.96 cal/g°C
Therefore, the specific heat of the substance is 0.96 cal/g°C.
reactivity is the ability of matter to combine chemically with other substances true or false
Answer:True?!
Explanation:
Can someone answer this please I will fix it tomorrow if i remember
Answer:
true
Explanation:
How many grams of sodium hydroxide pellets, NaOH, are required to prepare 50 mL
of a 0.15 M solution.
Answer:
[tex]\large \boxed{\text{0.30 g }}[/tex]
Explanation:
1. Calculate the moles of NaOH
[tex]\text{Moles of NaOH} = \text{0.050 L solution} \times \dfrac{\text{0.15 mol NaOH}}{\text{1 L solution}} = \text{0.0075 mol NaOH}[/tex]
2. Calculate the mass of NaOH
[tex]\text{Mass of NaOH } = \text{0.0075 mol NaOH } \times \dfrac{\text{40.00 g NaOH }}{\text{1 mol NaOH }} = \textbf{0.30 g NaOH}\\\\\text{You need $\large \boxed{\textbf{0.30 g of NaOH}}$ to prepare the solution}[/tex]
Like He, the Li2+ ion is a single-electron system (Problem 5.94). What wavelength of light in nm must be absorbed to
promote the electron in Li2+ from n = 1 to n = 4?
Answer:[tex]1.08\times 10^{-8}m[/tex]
Explanation:
Let [tex]E_{n}[/tex] be the energy of the electron in [tex]n[/tex]th orbit.
According to Bohr's model,
[tex]E_{n}=\frac{-kz^{2}}{n^{2}}[/tex]
where [tex]k=2.179\times 10^{-18}J[/tex]
[tex]Z[/tex] is the atomic number
[tex]n[/tex] is the orbit number.
Given,[tex]z=3[/tex]
Energy required for transition from [tex]n=1[/tex] to [tex]n=4[/tex] is [tex]\frac{k(3)^{2}}{1^{2}}-\frac{k(3)^{2}}{4^{2}}=\frac{15k\times 9}{16} =18.38\times 10^{-18}J[/tex]
Since,wave length is [tex]\frac{hc}{E}[/tex]
where [tex]h[/tex] is the plancks constant.
[tex]c[/tex] is the speed of light.
[tex]c=3\times 10^{8}\\h=6.63\times 10^{-34}m^{2}KgS^{-1}[/tex]
So,wave length is [tex]\frac{6.63\times 10^{-34} \times 3\times 10^{8}}{18.38\times 10^{-18}} =1.08\times 10^{-8}m[/tex]
Final answer:
To determine the wavelength of light absorbed by a Li2+ ion moving from n = 1 to n = 4, we use the Bohr model and adjust the Rydberg formula by the square of the nuclear charge. This yields the energy difference, which can be converted to wavelength using the relationship between energy, wavelength, and the speed of light.
Explanation:
The question involves using the Bohr model of the atom to calculate the wavelength of light that must be absorbed to excite an electron. For a single-electron system like the Li2+ ion, the energy difference between two orbits (n = 1 and n = 4) can be calculated using the Rydberg formula for hydrogen-like atoms:
E = Rydberg constant * (1/n12 - 1/n22)
Here, n1 and n2 are the principal quantum numbers of the initial and final states, respectively. Since the Li2+ ion has a higher nuclear charge than hydrogen, we must account for this by multiplying the Rydberg constant by the square of the nuclear charge (Z2). The energy of the photon absorbed is then transformed into a wavelength using the relationship:
c =
λ * E
Where c is the speed of light and
λ is the wavelength. By plugging in the appropriate values and constants, we can solve for the wavelength of light in nm.
What is a mixture of small pieces of rock with decayed plants and animals
Answer:
soil A mixture of weathered rock and decayed plants and animals. Plants need soil to grow. Soil is the top layer of Earth's land surface, in many places.
Explanation:
Soil is the mixture composed of eroded rocks, organic matter from decayed plants and animals, minerals, and other materials vital for plant growth and ecological foundations.
The material you're asking about, which is a mixture of small pieces of rock with decayed plants and animals, is known as soil. Soil is a blend of various components, including eroded rock, minerals, organic matter, and other materials. These ingredients are critical for supporting plant life and form the fundamental layers of terrestrial ecosystems.
The organic matter in soil typically comes from decaying plant and animal matter, which can vary from freshly fallen leaves to more fully decomposed materials, known as detritus. Additionally, soil may include biologic precipitates, fragments of rocks such as sand, silt, or clay, and in some cases, paths created by earthworms and burrows from moles.
If MnSO4 → MnO+SO3 is not a synthesis reaction, then what type of reaction is it?
single-displacement
decomposition
combustion
double-displacement
Answer: It would be decomposition :)
Answer:
MnSO₄ → MnO+SO₃ is a decomposition reaction.
Explanation:
In a decomposition reaction, a single substance breaks down or breaks down, producing two or more different substances. In other words, decomposition reactions are those that form two or more substances from a compound. In this reaction the atoms that form a compound are separated to give the products according to the formula:
AB → A + B
This type of reactions can occur spontaneously or caused by certain external factors, such as heat, that promote the breakdown of the molecule into simpler substances.
There are 3 types of decomposition reactions, depending on the external factor that causes the reaction:
If the decomposition is caused by a catalyst, it is called catalysis. If the decomposition occurs by the application of heat it is called thermal decomposition. If the decomposition is produced by the application of electric current, it is called electrolytic decomposition or electrolysis.Then MnSO₄ → MnO+SO₃ is a decomposition reaction.
10. What mass of glass (Cp = 0.749 J/gºC) is needed to absorb 5.00x104 J of heat, if it starts at 26.0 C and has a final temperature of 275.0°C?
Answer:
m = 0.03 × 10⁴ g
Explanation:
Given data:
Specific heat capacity = 0.749 j/g.°C
Heat absorbed = 5.0 × 10⁴ J
Initial temperature = 26.0 °C
Final temperature = 275.0 °C
Mass = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2-T1
ΔT = 275.0 °C - 26.0 °C
ΔT = 249 °C
Q = m.c. ΔT
m = Q / c. ΔT
m = 5.0 × 10⁴ J / 0.749 j/g.°C × 249 °C
m = 5.0 × 10⁴ J / 186.5 j/g
m = 0.03 × 10⁴ g
The mass of glass required to absorb 5.00x10⁴ J of heat with a temperature change from 26.0°C to 275.0°C, using a specific heat capacity of 0.749 J/g°C, is approximately 268 grams.
We can use the formula for heat absorption:
[tex]q = m \times C_p \times \Delta T[/tex]
where:
q is the heat absorbed (5.00x10⁴ J)m is the mass of the glassCp is the specific heat capacity (0.749 J/g°C)ΔT is the change in temperature ( [tex]275.0 \textdegree C - 26.0 \textdegree C = 249.0 \textdegree C[/tex])Let's rearrange the formula to solve for m:
[tex]m = q / (C_p \times \Delta T)[/tex]
Substituting in the given values:
[tex]m = 5.00 \times 10^4 J / (0.749 J/g \textdegree C \times 249.0 \textdegree C)[/tex]
Simplifying the calculation:
[tex]m = \frac {5.00 \times 10^4 J}{ 186.501 J/g} = 268 g[/tex]
So, the mass of the glass needed to absorb 5.00x10⁴ J of heat, with the given temperature change, is approximately 268 grams.
How do you read a data table?
Answer:
1st you read the column that has the subject then the tally column last you determine/read the frequency column
Explanation:
Water exist as a liquid between 0 and 100 Celsius.
a. True
b. False
a. True. Water exists as a liquid between 0 and 100 degrees Celsius.
Freezing Point: Water freezes at 0 degrees Celsius (32 degrees Fahrenheit). This is the temperature at which water starts to change from a liquid to a solid (ice) under normal atmospheric pressure.
Boiling Point: Boiling point of water is 100 degrees Celsius (212 degrees Fahrenheit). This is the temperature at which water changes from a liquid to a gas (steam) under normal atmospheric pressure.
2. I'm strong and stiff. Getting through me is TOUGH! I'm found only in plants and I guess that's
enough
Answer:
This is called a "cell wall'.
Explanation:
Answer: cell wall
Explanation:
How many moles of Na2SO4, are produced from 7.00 moles of (NH4)2SO4?
Answer:The number of mole in the compounds are:
A. 6.60 g of (NH₄)₂SO₄ contains 0.05 mole.
B. 4.5 kg Ca(OH)₂ contains 60.81 moles
The mole of a substance is related to its mass and molar mass according to the equation:
With the above formula, we can obtain the answer to the questions given above. This is illustrated below:
A. Determination of the number of mole in 6.60 g of (NH₄)₂SO₄
Molar mass of (NH₄)₂SO₄ = 2[14 + (4×1)] + 32 + (4×16)
= 2[14 + 4] + 32 + 64
= 2[18] + 32 + 64
= 36 + 32 + 64
= 132 g/mol
Mass of NH₄)₂SO₄ = 6.60 g
Mole of NH₄)₂SO₄ =?
Mole of NH₄)₂SO₄ =
Mole of NH₄)₂SO₄ = 0.05 mole
Thus, 6.60 g of (NH₄)₂SO₄ contains 0.05 mole.
B. Determination of the number of mole in 4.5 kg Ca(OH)₂
Molar mass of Ca(OH)₂ = 40 + 2(16 + 1)
= 40 + 2(17)
= 40 + 34
= 74 g/mol
Mass of Ca(OH)₂ = 4.5 kg
= 4.5 × 1000
= 4500 g
Mole of Ca(OH)₂ =?
Mole of Ca(OH)₂ =
Mole of Ca(OH)₂ = 60.81 moles
Thus, 4.5 kg Ca(OH)₂ contains 60.81 moles
Learn more: brainly.com/question/17201079
What's the mass of 14.4 mol F2
Answer:
Mass = 547.2 g
Explanation:
Given data;
Mass of F₂ = ?
Moles of F₂ = 14.4 mol
Solution:
Formula
Number of moles = mass/ molar mass
Mass = number of moles × molar mass
Molar mass of F₂ = 38 g/mol
Mass = 14.4 mol × 38 g/mol
Mass = 547.2 g
The mass of 14.4 moles of F₂ is 547.2 grams.
To solve this, we need to know the molar mass of fluorine gas (F₂). Each fluorine atom has an atomic mass of approximately 19.0 g/mol. Since F₂ is a diatomic molecule, its molar mass is:
19.0 g/mol × 2 = 38.0 g/mol
Now, we multiply the molar mass by the number of moles given:
14.4 mol × 38.0 g/mol = 547.2 g
Thus, the mass of 14.4 moles of F₂ is 547.2 grams.
Write a method that could be used to produce pure crystals of copper chloride from copper oxide and hydrochloric acid.
-Describe how you would make the salt from the reactants.
-Describe how you would purify the salt from the reaction mixture.
- Describe how you would make the salt from the reactants.
CuO + 2 HCl → CuCl₂ + H₂O
- Describe how you would purify the salt from the reaction mixture.
Filter the solution and let the product crystallize.
Explanation:
The reaction between copper oxide (CuO) and hydrochloric acid (HCl) will produce copper chloride (CuCl₂) and water:
CuO + 2 HCl → CuCl₂ + H₂O
-Describe how you would make the salt from the reactants
In a beaker which contain cooper oxide add the hydrochloric acid. To avoid working with concentrated hydrochloric acid, the acid may be diluted with water but make sure the add the stoechiometric amount (and a little bit of excess) in respect with the copper oxide.
-Describe how you would purify the salt from the reaction mixture.
Let the reaction proceed and then filter the solution to remove the unreacted cooper oxide.
Let the filtered solution, which contain copper chloride, water and unreacted hydrochloric acid, to stand undisturbed for several days. You may see the crystals growing from the solution. To speed up the process you may reduce the temperature.
Learn more about:
purifying compounds
https://brainly.com/question/5586971
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To produce pure crystals of copper chloride, react copper oxide with hydrochloric acid to form copper chloride and water, then purify by filtration and evaporation to obtain copper chloride crystals.
Explanation:To produce pure crystals of copper chloride from copper oxide and hydrochloric acid, the reaction involves a simple acid-base reaction, following the general word equation: acid + metal oxide → salt + water. First, copper oxide would react with hydrochloric acid to form copper chloride and water. This reaction can be represented by the equation CuO(s) + 2HCl(aq) → CuCl2(aq) + H2O(l).
To purify the copper chloride, the resulting mixture would need to be filtered to remove any unreacted copper oxide. Then, the copper chloride solution would be evaporated to obtain the crystals. This evaporation could either be done by gently heating the solution to accelerate the process or by allowing the water to evaporate naturally over time.
An insect population increases and then decreases as the food supply changes.
Which activity does this demonstrate?
self-regulation
uncontrolled population explosion
self-restoration
unchecked exponential growth
plz help i dont understand.. T.T
Answer:
self regulation
Explanation:
Answer:
A) Self-regulation
Explanation:
A self-regulated organism takes measures to balance its own survival with the scarce resources that the enviroment offers. In this case, the insect population is self-regulating because it is responding to changes in the food supply, and adapts itself accordingly.
In a way, self-regulation is like supply and demand. As supply of food decreases, but demand stays the same, scarcity ensues. This causes the need to reduce demand until a new equilibrium is reached, where demand and supply are equal.
A compound is found to be 3 percent hydrogen, 32 percent phosphorus, and 65 percent oxygen. What is the empirical formula of this compound?
HPO
HPO4
H(PO4)3
H3PO4
Answer:
Empirical formula is H₃PO₄
Explanation:
Given data:
Percentage of hydrogen = 3%
Percentage of P = 32%
Percentage of oxygen = 65%
Empirical formula = ?
Solution:
Number of gram atoms of H = 3 / 1= 3
Number of gram atoms of O = 65 / 16 = 4.06
Number of gram atoms of P = 32 / 31 = 1.03
Atomic ratio:
H : P : O
3/1.03 : 1.03/1.03 : 4.06/1.03
3 : 1 : 4
H : P : O = 3 : 1 : 4
Empirical formula is H₃PO₄.
What is quantum model of the atom often called.
Answer:
Quantum mechanics or physics
Explanation:
What is the oxidation half-reaction for iron?
Answer:
Fe → Fe⁺³ + 3e⁻
Explanation:
The oxidation half reaction for iron is:
Fe → Fe⁺³ + 3e⁻
Other options are incorrect because,
A) 3e⁻ + Fe → Fe³⁺
This is incorrect because when three electrons are gained by any atom it will gain negative three charge not positive.
C) 6e⁻ + 2Fe → 2Fe³⁺
This is incorrect because when six electrons are gained by any atom it will gain negative six charge not positive.
d) Fe → 2Fe³⁺ + 6e⁻
Its also incorrect because iron atoms are not balanced on both side of equation.
3)
How many atoms are in 14 moles of cadmium?
Answer:
[tex]8.4322\times10^{24} atoms[/tex] atoms are in 14 moles of cadmium.
Explanation:
Cadmium is a white and silvery metal that is found in the curst of the earth.During the production process of metals such as lead, copper, zinc, cadmium is extracted
Cadmium is present in some foods and is emitted when fossil fuels like as coal and oil is used, smoking cigarettes. It is used in craft glazes, metal batteries, and coatings.
We know that 1 mole of Cadmium (Cd contains) 6.023*1023 atoms, which is Avogadro's number.
So in 14 Grams of Cadmium, the number of atoms present is,
=>14×number atoms present in one cadmium atom
=>[tex]14\times 6.023\times10^{23}[/tex]
=>[tex]8.4322\times10^{24} atoms[/tex]
The number of atoms of Cadmium present in 14 moles is 84.322 [tex]\rm \bold{\times\;10^2^3}[/tex] atoms.
The number of atoms in a mole of compounds can be given by the Avagadro number. The Avagadro number has been equal to 6.023 [tex]\rm \bold{\times\;10^2^3}[/tex]
Thus, 1 mole = 6.023 [tex]\rm \bold{\times\;10^2^3}[/tex] atoms
The given element has been Cadmium. The moles of Cadmium is 14 moles.
By simplifying with unitary method:
1 mole = 6.023 [tex]\rm \bold{\times\;10^2^3}[/tex] atoms
14 moles = [tex]\rm \dfrac{6.023\;\times\;10^2^3}{1}\;\times\;14[/tex] atoms
14 moles of Cadmium = 84.322 [tex]\rm \bold{\times\;10^2^3}[/tex] atoms.
The number of atoms of Cadmium present in 14 moles is 84.322 [tex]\rm \bold{\times\;10^2^3}[/tex] atoms.
For more information about atoms in a mole, refer to the link:
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how many d electrons are found in cobalt
Answer:
7
Explanation:
Because cobalt's a transition metal, the 7 'd'-type electrons can count as valence electrons, though they rarely react with anything.
A 1.0 g sample of hydrogen reacts completely with 19.0 g of fluorine to form a compound of
hydrogen and fluorine. What is the percent composition by mass of hydrogen in this
compound?
Answer: hydrogen has 0.0504% and Fluorine has 0.950%
Explanation: H= 1.00794
F= 18.9984
1 X 1.00794+ 1 X 18.9984= 20.00778g/mol
H= 1.00794/20.00778= 0.0504%
F-18.9984/20.00778= 0.950%
In H2SO4, the oxidation number of H is , that of S is , and that of O is .
Answer:
Oxidation State of H in H₂SO₄ = +1
Oxidation State of S in H₂SO₄ = +6
Oxidation State of O in H₂SO₄ = -2
Explanation:
Oxidation number:
oxidation number is an apparent charge of an atom in a compound.
the total charge on a compound is zero
So for H₂SO₄ total charge = 0
Hydrogen donate an electron in H₂SO₄ and have +1 charge that is oxidation number
***so to calculate oxidation number of Sulfur and Oxygen in H₂SO₄
oxygen have 2- state
O.N. of H = 1+
O.N. of O = 2-
O.N. of S = x
H₂SO₄ =0
put values
(+1)2 + S + (-2)4=0
+2 + S -8 =0
S = 0-2 + 8
S = +6
****Now to find oxidation number of Oxygen
O.N. of H = 1+
O.N. of O = x
O.N. of S = +6
H₂SO₄ =0
put values
(+1)2 + (+6) + (O)4=0
+2 + 6 - (O) 4 =0
(O)4 = 0-2 - 8
(O)4 = -8
O = -8/4
O = -2
***Now to find oxidation number of Oxygen
O.N. of H = 1+
O.N. of O = x
O.N. of S = +6
H₂SO₄ =0
put values
(H)2 + (+6) + (-2)4=0
(H)2 + 6 - 8 =0
(H)2 = 0 - 6 + 8
(H)2 = +2
H = +2/2
H = +1
For each of the four single-displacement reactions, describe what happened in rachel well. if a chemical reaction occured, write a balanced equation for it. Then using the A, B symbols, write a general equation for a single-displacement reaction.
Answer:
Explanation:
Single replacement:
It is the reaction in which one elements replace the other element in compound.
General equation:
AB + C → AC + B
1) zinc and Copper sulfate
Zn + CuSO₄ → ZnSO₄ + Cu
Zinc is more reactive than copper it displaces the copper from copper sulfate and form zinc sulfate.
2) Aluminium and Copper sulfate
2Al + 3CuSO₄ → Al₂(SO₄)₃ + 3Cu
Aluminium is more reactive than copper it displaces the copper from copper sulfate and form aluminium sulfate.
3) Zinc and silver nitrate
Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag
zinc is more reactive than silver it displaces the silver from silver nitrate and form zinc nitrate.
4) copper and silver nitrate
Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
copper is more reactive than silver it displaces the silver from silver nitrate and form copper nitrate.
Final answer:
In a single-displacement reaction, one element replaces another element in a compound. The general equation for a single-displacement reaction is A + BC → AC + B.
Explanation:
In a single-displacement reaction, one element replaces another element in a compound. These reactions occur when a more reactive element displaces a less reactive element from its compound.
For example, in the reaction F2 + FeI3, fluorine (F2) replaces iodine (I) in the compound FeI3, resulting in the formation of FeF3:
2F2 + FeI3 → 2FeF3 + 3I2
The general equation for a single-displacement reaction can be written as A + BC → AC + B, where A is the more reactive element that displaces B from its compound BC.
Consider the following intermediate chemical equations.
What is the enthalpy of the overall chemical reaction?
-999 kJ
-250. kJ
250. kJ
999 kJ
Answer:
999 kJ
Explanation:
Given are two reactions with enthalpies Δ[tex]H_1=-2,439\ kJ[/tex] and Δ[tex]H_2=3,438\ kJ[/tex]
We know enthalpy is an additive property.
Thus the overall chemical equation can be obtained from adding both the two elementary equations.
Therefore the overall enthalpy is the summation of enthalphy change in each equation.
Δ[tex]H_{overall} =[/tex]Δ[tex]H_1+[/tex]Δ[tex]H_2[/tex]
Δ[tex]H_{overall}[/tex] [tex]=-2,439+3,438=999\ kJ[/tex]
Therefore the overall enthalpy is 999 kJ.
Answer: D
Explanation:
just took it
7. If you plotted atomic radius versus first ionization
energy, would the graph reveal a direct or inverse
relationship?
Answer:
Neither
Explanation:
I plotted the graph of atomic radius vs. ionization energy for the first 10 elements.
It shows neither a direct nor an inverse relationship.
However, it is clear that atomic size decreases as ionization energy increases.
Plotting atomic radius against first ionization energy reveals an inverse relationship; as atomic radius increases, the first ionization energy typically decreases.
Explanation:If you plotted atomic radius versus first ionization energy, the graph would reveal an inverse relationship. This is because, generally, as atomic radius increases, the first ionization energy decreases. The ionization energy is affected by the principal quantum number (n) and the effective nuclear charge (Zeff), which relates to the strength of attraction between the nucleus and the valence electrons. Hence, a larger atomic radius means that the valence electrons are further from the nucleus and more shielded by other electrons, reducing the energy required to remove them. When plotting a graph of atomic radius versus first ionization energy, one would observe that points on the graph move downward as you go from top to bottom (from elements with a smaller atomic radius and higher ionization energy to elements with a larger atomic radius and lower ionization energy).
Volume of 0.150 M NaOH solution required to neutralize 25mL of a 0.055 M HCl solution?
Equation of the reaction: NaOH(aq) + HCl(aq) ——-> H2O(l) + NaCl(aq)
9.17 mL
Explanation:In this question we are given;
Molarity of NaOH as 0.150 MMolarity of the acid, HCl as 0.055 MVolume of the acid, HCl as 25 mLEquation for the reaction as;NaOH(aq) + HCl(aq) → H2O(l) + NaCl(aq)
We are required to determine the volume of the alkali, NaOH used;
Step 1: Determine the moles of the acid, HClMolarity = Number of moles ÷ Volume
Thus, rearranging the formula;
Moles = Molarity × volume
= 0.055 M × 0.025 L
= 0.001375 moles
Step 2: Moles of the alkali, NaOHFrom the reaction; 1 mole of HCl reacts with 1 mole of NaOHTherefore;
Moles of HCl = Moles of NaOHHence; Moles of NaOH = 0.001375 moles
Step 3: Determine the volume of the alkali, NaOHFrom the previous equation;Molarity = Moles ÷ Volume
Rearranging the equation;Volume = Moles ÷ Molarity
Therefore;
Volume of NaOH = 0.001375 moles ÷ 0.150 M
= 0.00917 L, but, 1 L = 1000 mL
= 9.17 mL
Therefore, the volume of NaOH required is 9.17 mL
Apply the ideal gas law to solve problems
Question
A sample of gas that contains 21.0 moles at a pressure of 78.0 atm with a temperature of 900. Khas what volume?
• Use R = 0.08206 La
for the gas constant.
Answer:
Volume of gas ( V ) = 19.8935 L
Explanation:
Data Given:
no. of mole of gas (n) = 21.0 mole
Pressure P = 78.0 atm
Temperature T = 900 K
Ideal gas constant = 0.08206 L atm K⁻¹ mol⁻¹
Volume of gas = ?
Formula used for Ideal gases
PV = nRT
As we have to find volume of the gas:
We will rearrange the ideal gas equation as below:
V = nRT / P ........................................... (1)
Put value in equation (1)
V = 21.0 mol x 0.08206 L atm K⁻¹ mol⁻¹ x 900K / 78.0 atm
V = 19.8935 L
Volume of gas V = 19.8935 L
isotopes of the same element must also have the same?
a) number of alpha particles
b) average mass number
c) atomic number
d) number of neutrons
Answer:
The correct answer is c atomic number
Explanation:
When two atoms contain same atomic number or proton number then these two atoms are called isotopes of each other.
For example protium and tritium are isotopes of each other as they contain same atomic number that is 1.
Which answer accurately describes the difference between speed and velocity? Read each answer choice carefully.
Question 4 options:
A. If speed is constant, then velocity is also constant.
B. Speed requires direction. The direction doesn't matter when calculating velocity.
C. Speed is the distance per unit of time. Velocity is the displacement per unit of time.
Answer:
C. Speed is the distance per unit of time. Velocity is the displacement per unit of time.
This answer accurately describes the difference between speed and velocity.
Explanation:
A. If speed is constant, then velocity is also constant.
The above statement is not correct, the correct statement is if speed is constant its velocity is not necessarily constant.
Example: An object in uniform circular motion has constant speed but its velocity changes at every instant due to change in direction.
B. Speed requires direction. The direction doesn't matter when calculating velocity.
The above statement is not correct, the correct statement is
Speed does not require direction. The direction is necessary for calculating velocity.
Speed, a scalar quantity, requires magnitude only not the direction.
Velocity is vector quantity, requires magnitude as well as direction.
C. Speed is the distance per unit of time. Velocity is the displacement per unit of time.
The above statement is correct i.e.
Speed is the distance per unit of time. Velocity is the displacement per unit of time.
4. Why do elements in the same family generally have similar properties?
Elements in the same family have similar properties because they share the same number and distribution of valence electrons, leading to similar chemical behaviors. Group patterns like the alkali metals in Group 1A with one valence electron contribute to these predictable reactivity patterns. Trends, such as increasing metallic character down a group, are also observed.
Elements in the same family or group of the periodic table generally have similar properties because they have the same number and distribution of electrons in their valence shells. This similarity in electron configuration explains their comparable chemical behaviors. For instance, all elements in Group 1A have one valence electron, which leads to common reactivity patterns and they are known as the alkali metals. As we progress along a group, there are also trends, such as an increase in metallic character from nonmetals like oxygen to metals like polonium.
In the 19th century discoveries, similar compounds formed by the reactions of elements such as lithium, sodium, and potassium with other elements underscored the pattern of similar chemical properties within a group. The figure from the provided reference indicates that within a group, elements have the same s and p valence electron configurations, which play a crucial role in their reactions and interactions.
Therefore, the periodic table is deliberately structured to group elements with similar properties, following the patterns of electron configurations, specifically within their valence shells, resulting in the elements' predictable chemical behavior. This order mirrors the sequential filling of electron subshells, ensuring that elements in a family react similarly in chemical reactions.
How is a chemical equation used to represent a chemical reaction?
1. The atoms on the left side of the arrow are different from the atoms on the right, but are arranged similarly.
2. The atoms on the left side of the arrow are different from the atoms on the right, and are arranged differently.
3. The atoms on the left side of the arrow are the same as the atoms on the right, but are arranged differently.
4. The atoms on the left side of the arrow are the same as the atoms on the right, and are arranged the same.
Answer:
3. The atoms on the left side of the arrow are the same as the atoms on the right, but are arranged differently.
Explanation:
A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.
For example:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen. The number of atoms are same on both side however arrangement of atoms is different.
As the ball falls, its energy will decrease and its energy will increase
Answer: As an object falls its potential energy decreases, while its kinetic energy increases. The decrease in potential energy is exactly equal to the increase in kinetic energy.
Explanation: