Q: Which of the following is the correct expression for Dalton's Law of Partial Pressures for a mixture of three gases?

$$P_{\text{total}} = P_1$ + P_2$ + P_3$

Q: Which of the following is the correct formula for calculating the enthalpy change ($$\Delta H) of a $$reaction using standard enthalpies of formation?

$$\Delta H = \sum n \Delta H_f$$^{\circ}$$ (\text{products}) - \sum n \Delta H_f$$^{\circ}$$ (\text{reactants})$$

Question 1

Which of the following best describes a strong electrolyte in aqueous solution?

Accepted Answer

A substance that completely dissociates into ions when dissolved in water.

Question 2

A student prepares a solution by dissolving 5.00 g of NaCl in enough water to make 250.0 mL of solution. What is the molarity of the solution? (Molar mass of NaCl = 58.44 g/mol)

Accepted Answer

$$0.342\ \mathrm{M}$$

Question 3

Which of the following is a correct net ionic equation for the reaction between aqueous solutions of silver nitrate and sodium chloride?

Accepted Answer

$$\mathrm{Ag}^+ (aq) + \mathrm{Cl}^- (aq) \rightarrow \mathrm{AgCl} (s)$$

Question 4

Which of the following statements about gases is TRUE according to the kinetic molecular theory?

Accepted Answer

Gas particles are in constant, random motion and collisions between them are perfectly elastic.

Question 5

A 2.00 L container holds 0.500 mol of O$$_2$$ gas at 27$$^\circC. $$What is the pressure of the gas in atmospheres? (Use $$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$})$$

Accepted Answer

$$6.15\ \mathrm{atm}$$

Question 6

Which of the following best explains why water boils at a lower temperature at high altitudes?

Accepted Answer

The atmospheric pressure is lower, so water molecules require less energy to escape into the vapor phase.

Question 7

Which of the following is the correct expression for Dalton's Law of Partial Pressures for a mixture of three gases?

Accepted Answer

$$P_{	ext{total}} = P_1$ + P_2$ + P_3$

Question 8

A sample of gas occupies 4.00 L at 1.00 atm and 300 K. If the pressure is increased to 2.00 atm and the temperature is decreased to 200 K, what is the new volume of the gas?

Accepted Answer

$$1.33\ \mathrm{L}$$

Question 9

Which of the following is a state function?

Accepted Answer

Enthalpy ($$H)$$

Question 10

Which of the following reactions is exothermic?

Accepted Answer

Combustion of methane: $$\mathrm{CH}_4 (g) + 2\mathrm{O}_2 (g) \rightarrow \mathrm{CO}_2 (g) + 2\mathrm{H}_2\mathrm{O} (g)$$

Question 11

Which of the following best describes Hess's Law?

Accepted Answer

The enthalpy change for a reaction is the same, regardless of the number of steps or pathway taken.

Question 12

Which of the following is the correct formula for calculating the enthalpy change ($$\Delta H) of a $$reaction using standard enthalpies of formation?

Accepted Answer

$$\Delta H = \sum n \Delta H_f$$^{\circ}$$ (	ext{products}) - \sum n \Delta H_f$$^{\circ}$$ (	ext{reactants})$$

Question 13

A balloon filled with helium gas has a volume of 2.50 L at 1.00 atm and 298 K. If the balloon rises to a higher altitude where the pressure is 0.800 atm and the temperature is 273 K, what is the new volume of the balloon?

Accepted Answer

$$2.73\ \mathrm{L}$$

Question 14

Which of the following best explains why real gases deviate from ideal behavior at high pressures and low temperatures?

Accepted Answer

Intermolecular forces and the finite volume of gas particles become significant.

Question 15

Which of the following is the correct balanced equation for the combustion of propane ($$\mathrm{C}_3\mathrm{H}_8$$)?

Accepted Answer

$$\mathrm{C}_3\mathrm{H}_8 (g) + 5\mathrm{O}_2 (g) \rightarrow 3\mathrm{CO}_2 (g) + 4\mathrm{H}_2\mathrm{O} (g)$$

Question 16

Which of the following best describes the difference between heat capacity and specific heat capacity?

Accepted Answer

Heat capacity is the amount of heat required to raise the temperature of an object by 1 K, while specific heat capacity is the amount of heat required to raise the temperature of 1 gram of a substance by 1 K.

Question 17

Which of the following is a renewable energy alternative that can help address excessive CO$$_2 in $$the atmosphere?

Accepted Answer

Solar power

Question 18

A reaction has $$\Delta H = -250\ \mathrm{kJ}$$ and $$\Delta S = +100\ \mathrm{J/K}. At $$what temperature (in K) does the reaction become non-spontaneous? (Use $$\Delta G = \Delta H - T\Delta S)$$

Accepted Answer

$$2500\ \mathrm{K}$$

Question 19

Which of the following is the correct relationship for Boyle's Law?

Accepted Answer

$$P_1$$ $$V_1$$ = $$P_2$$ $$V_2$$

General Chemistry Study Guide: Solutions, Gases, and Thermochemistry

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