1) Which of the following does NOT represent a specific element in its standard state? Optional Answers:

1. Mg(s)

2. Br2(l)

3. Hg(l)

4. H(g)

 

2. For which of the following reaction equations would the enthalpy of the reaction be equal to the standard molar enthalpy of formation of solid sodium fluoride?

Optional Answers:

1. 2Na(s) + F2(g) -> 2NaF(s)

2. Na(s) + 1/2F2(g) -> NaF(s)

3. Na(s) + F(g) -> NaF(s)

4. Na+(g) + F-(g) -> NaF(s)

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10.7

1. How many of which type(s) of bond(s) would need to be broken to completely break apart one mole of carbon disulfide? Optional Answers:

1. Two carbon-sulfur triple bonds

2. Two carbon-sulfur single bonds

3. Two carbon-sulfur double bonds

4. Four carbon-sulfur single bonds

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11.1

1. A sample of each of the following gases is held at 300 K. Which gas particles will have the HIGHEST average molecular speed? Optional Answers:

1. Argon

2. Helium

3. Neon

4. Krypton

 

2. Which of the following gases will have the SLOWEST rate of diffusion? Optional Answers:

1. Fluorine

2. Neon

3. Argon

4. Chlorine

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11.4

1. Which of the following changes would lead to a DECREASE in the volume of a gas? Optional Answers:

1. Increasing the number of moles of gas

2. Increasing the temperature

3. Increasing the external pressure

 

2. According to the equation H2(g) + Cl2(g) -> 2HCl(g), how many liters of HCl(g) will be formed when 2.0 L of H2(g) react with 3.0 L of Cl2(g)? Pressure and temperature are constant Optional Answers:

1. 2.0 L

2. 3.0 L

3. 6.0 L

4. 4.0 L

 

3. A confined sample of gas at a constant external pressure has a certain volume at 27 degrees C. At what temperature, in degrees C, will the volume of the gas be doubled? Optional Answers:

1. 54 C

2. 873 C

3. 600 C

4. 327 C

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11.5

1. Which of the following gases would have the HIGHEST density at STP? Optional Answers:

1. Krypton (Kr)

2. Xenon (Xe)

3. Radon (Rn)

4. Argon (Ar)

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11.6

1. Gases will behave MOST ideally at: Optional Answers:

1. High temperatures and high pressures

2. Low temperatures and low pressures

3. Low temperatures and high pressures

4. High temperatures and low pressures

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11.7

1. To calculate the TOTAL pressure of gases in a mixture, the individual partial pressures should be: Optional Answers:

1. Divided

2. Multiplied

3. Subtracted

4. Added

 

Answers only. For the explanations, please refer to the next part.

10.6

1. Which of the following does NOT represent a specific element in its standard state? Optional Answers:

1. Mg(s)

2. Br2(l)

3. Hg(l)

4. H(g)

 

2. For which of the following reaction equations would the enthalpy of the reaction be equal to the standard molar enthalpy of formation of solid sodium fluoride?

Optional Answers:

1. 2Na(s) + F2(g) -> 2NaF(s)

2. Na(s) + 1/2F2(g) -> NaF(s)

3. Na(s) + F(g) -> NaF(s)

4. Na+(g) + F-(g) -> NaF(s)

 

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10.7

1. How many of which type(s) of bond(s) would need to be broken to completely break apart one mole of carbon disulfide? Optional Answers:

1. Two carbon-sulfur triple bonds

2. Two carbon-sulfur single bonds

3. Two carbon-sulfur double bonds

4. Four carbon-sulfur single bonds

 

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11.1

1. A sample of each of the following gases is held at 300 K. Which gas particles will have the HIGHEST average molecular speed? Optional Answers:

1. Argon

2. Helium

3. Neon

4. Krypton

 

2. Which of the following gases will have the SLOWEST rate of diffusion? Optional Answers:

1. Fluorine

2. Neon

3. Argon

4. Chlorine

 

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11.4

1. Which of the following changes would lead to a DECREASE in the volume of a gas? Optional Answers:

1. Increasing the number of moles of gas

2. Increasing the temperature

3. Increasing the external pressure

 

 

2. According to the equation H2(g) + Cl2(g) -> 2HCl(g), how many liters of HCl(g) will be formed when 2.0 L of H2(g) react with 3.0 L of Cl2(g)? Pressure and temperature are constant Optional Answers:

1. 2.0 L

2. 3.0 L

3. 6.0 L

4. 4.0 L

 

 

3. A confined sample of gas at a constant external pressure has a certain volume at 27 degrees C. At what temperature, in degrees C, will the volume of the gas be doubled? Optional Answers:

1. 54 C

2. 873 C

3. 600 C

4. 327 C

 

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11.5

1. Which of the following gases would have the HIGHEST density at STP? Optional Answers:

1. Krypton (Kr)

2. Xenon (Xe)

3. Radon (Rn)

4. Argon (Ar)

 

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11.6

1. Gases will behave MOST ideally at: Optional Answers:

1. High temperatures and high pressures

2. Low temperatures and low pressures

3. Low temperatures and high pressures

4. High temperatures and low pressures

 

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11.7

1. To calculate the TOTAL pressure of gases in a mixture, the individual partial pressures should be: Optional Answers:

1. Divided

2. Multiplied

3. Subtracted

4. Added

Step-by-step explanation

Answers with explanations

10.6

 

1. Which of the following does NOT represent a specific element in its standard state? Optional Answers:

1. Mg(s)

2. Br2(l)

3. Hg(l)

4. H(g)

Explanation: Hydrogen in its standard state is H₂(g), not H(g).

 

2. For which of the following reaction equations would the enthalpy of the reaction be equal to the standard molar enthalpy of formation of solid sodium fluoride?

Optional Answers:

1. 2Na(s) + F2(g) -> 2NaF(s)

2. Na(s) + 1/2F2(g) -> NaF(s)

3. Na(s) + F(g) -> NaF(s)

4. Na+(g) + F-(g) -> NaF(s)

Explanation: The standard molar enthalpy of formation involves the formation of one mole of a compound from its constituent elements in their reference state.

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10.7

1. How many of which type(s) of bond(s) would need to be broken to completely break apart one mole of carbon disulfide? Optional Answers:

1. Two carbon-sulfur triple bonds

2. Two carbon-sulfur single bonds

3. Two carbon-sulfur double bonds

4. Four carbon-sulfur single bonds

Explanation: The structure of carbon disulfide is made of two carbon-sulfur bonds S=C=S. The molecule is linear, much like CO₂.

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11.1

1. A sample of each of the following gases is held at 300 K. Which gas particles will have the HIGHEST average molecular speed? Optional Answers:

1. Argon

2. Helium

3. Neon

4. Krypton

Explanation: The molecular speed is inversely proportional to the square root of the molar mass of a gas. The gas with the highest average molecular speed should have the lowest molar mass. Among the choices, helium (MW =4.003 g/mol) has the lowest molar mass.

2. Which of the following gases will have the SLOWEST rate of diffusion? Optional Answers:

1. Fluorine

2. Neon

3. Argon

4. Chlorine

Explanation: The rate of diffusion of a gas is inversely proportional to the square root of its molar mass. A gas that diffuses slowly has a high molar mass. Among the choices, chlorine gas (Cl₂) has the highest molar mass (MW = 70.9 g/mol).

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11.4

1. Which of the following changes would lead to a DECREASE in the volume of a gas? Optional Answers:

1. Increasing the number of moles of gas

2. Increasing the temperature

3. Increasing the external pressure

Explanation: According to Boyle's law, the volume of a gas is inversely proportional to its pressure. An increase in the pressure of a gas results to a decrease on its volume.

 

2. According to the equation H2(g) + Cl2(g) -> 2HCl(g), how many liters of HCl(g) will be formed when 2.0 L of H2(g) react with 3.0 L of Cl2(g)? Pressure and temperature are constant Optional Answers:

1. 2.0 L

2. 3.0 L

3. 6.0 L

4. 4.0 L

Explanation: According to Avogrado's law, at constant pressure and temperature, the volume of a gas is directly proportional to its amount. In the given reaction, H₂ is limiting since it has a lower volume. For every 1 mole of H₂ gas, 2 moles of HCl gas is formed. Since Avogadro's law applies, 2.0 L of H₂ will react with 2.0 L of Cl₂ to produce 4 L of HCl gas. A volume of 1.0 L Cl₂ gas should be left after the reaction.

 

3. A confined sample of gas at a constant external pressure has a certain volume at 27 degrees C. At what temperature, in degrees C, will the volume of the gas be doubled? Optional Answers:

1. 54 C

2. 873 C

3. 600 C

4. 327 C

Explanation: According to Charles' law, the volume of a gas is directly proportional to its temperature (in Kelvin). In Kelvin 27 degrees C is 300K. A gas with twice the volume will have double this temperature. That is, at 600 K. Converted to degree Celsius, this is equal to 327 C.

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11.5

1. Which of the following gases would have the HIGHEST density at STP? Optional Answers:

1. Krypton (Kr)

2. Xenon (Xe)

3. Radon (Rn)

4. Argon (Ar)

Explanation: The density of gas is related to its molar mass according to the equation ρ (density) = PM/RT. Therefore, the density is directly proportional to the molar mass. The densest of the gas should have the highest molar mass. Among the given choices, radon has the largest molar mass and therefore the largest density.

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11.6

1. Gases will behave MOST ideally at: Optional Answers:

1. High temperatures and high pressures

2. Low temperatures and low pressures

3. Low temperatures and high pressures

4. High temperatures and low pressures

Explanation: At low temperature, gases behave ideally as the effect of intermolecular forces between particles become negligible. At high temperatures, gases behave ideally as collisions between gas particles become elastic due to the increase in their molecular speeds.

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11.7

1. To calculate the TOTAL pressure of gases in a mixture, the individual partial pressures should be: Optional Answers:

1. Divided

2. Multiplied

3. Subtracted

4. Added

Explanation: The total pressure of a gas mixture is the sum of the partial pressures of each of its components.