Q: Which of the following equalities shows an incorrect relationship between pressure units?

$$60.0\ \text{kPa} = 450.\ \text{mm Hg}$$

Q: Which of the following best explains why $$\text{HF} in $$water has a higher boiling point than $$\text{HCl} in $$water?

Hydrogen bonding between $$\text{HF}$$ and water molecules

Question 1

Which of the following equalities shows an incorrect relationship between pressure units?

Accepted Answer

$$60.0\ 	ext{kPa} = 450.\ 	ext{mm Hg}$$

Question 2

A 5.00-L tank contains BrCl gas at $$1.2\ 	ext{atm}$$ and $$35\ ^\circ	ext{C}. $$What is the density (g/L) of BrCl under these conditions? (Molar mass of BrCl = 115.36 g/mol)

Accepted Answer

$$2.7$$

Question 3

According to kinetic molecular theory, which gas will have the highest root-mean-square velocity at $$150\ ^\circ	ext{C}$$?

Accepted Answer

$$	ext{H}_2$$

Question 4

A sample of gas is placed in a $$2.0\ 	ext{L}$$ balloon at $$25\ ^\circ	ext{C}$$ and $$1.5\ 	ext{atm}. $$The balloon is heated to $$40\ ^\circ	ext{C}$$ and pressurized to $$0.50\ 	ext{atm}. $$What is the final volume (L) of the gas?

Accepted Answer

$$6.3$$

Question 5

Which of the following substances exhibits only dispersion forces as its strongest intermolecular force?

Accepted Answer

$$	ext{N}_2$$

Question 6

A solution is made by dissolving $$95\ 	ext{mg} of $$caffeine ($$	ext{C}_8	ext{H}_{10}	ext{N}_4	ext{O}_2) in$$ $$200.\ 	ext{mL} of $$water. What is the mass percent of caffeine in this solution?

Accepted Answer

$$0.047\%$$

Question 7

The Henry’s law constant for $$	ext{CO}_2 in $$water at $$25\ ^\circ	ext{C} is$$ $$3.4 	imes 10$$^{-2}$$\ 	ext{mol}/	ext{L}\cdot	ext{atm}. $$What is the concentration (mol/L) of $$	ext{CO}_2 in a $$soda bottled with a partial pressure of $$5.0\ 	ext{atm}$$?

Accepted Answer

$$0.17$$

Question 8

Which of the following phase changes is exothermic?

Accepted Answer

Condensation

Question 9

A solution is made by dissolving $$50.\ 	ext{g}$$ $$	ext{MgCl}_2 in$$ $$500.\ 	ext{g}$$ $$	ext{H}_2	ext{O}. $$The vapor pressure of pure water at $$25\ ^\circ	ext{C} is$$ $$23.8\ 	ext{torr}. $$What is the vapor pressure (torr) of the solution? (Assume complete dissociation of $$	ext{MgCl}_2.)$$

Accepted Answer

$$21.6$$

Question 10

Which of the following is the strongest type of intermolecular force?

Accepted Answer

Ion-dipole attraction

Question 11

A reaction is second order with $$k = 4.3 	imes 10$$^{-3}$$\ 	ext{M}^{-1}	ext{s}^{-1}. $$How long (s) will it take for a $$5.0\ 	ext{M}$$ sample to decompose to $$1.75\ 	ext{M}$$?

Accepted Answer

$$240$$

Question 12

It takes $$40.\ 	ext{minutes}$$ for a sample to decompose by first order kinetics from $$1.6\ 	ext{M} to$$ $$0.40\ 	ext{M}. $$What is the value of the rate constant, $$k$$?

Accepted Answer

$$0.035\ 	ext{min}^{-1}$$

Question 13

Given the following data, what is the rate law for the reaction?

Experiment 1: $$[A]_0 = 0.450\ 	ext{M}$$, $$[B]_0 = 0.450\ 	ext{M}$$, Rate $$= 1.8 	imes 10$$^{-4}$$\ 	ext{M/s}$$
Experiment 2: $$[A]_0 = 0.450\ 	ext{M}$$, $$[B]_0 = 0.900\ 	ext{M}$$, Rate $$= 1.8 	imes 10$$^{-4}$$\ 	ext{M/s}$$
Experiment 3: $$[A]_0 = 0.900\ 	ext{M}$$, $$[B]_0 = 0.450\ 	ext{M}$$, Rate $$= 7.2 	imes 10$$^{-4}$$\ 	ext{M/s}$$

Accepted Answer

$$	ext{Rate} = k [A]^2$$

Question 14

The normal freezing point of ethanol is $$-114.6\ ^\circ	ext{C}$$, and $$K_f = 1.99\ ^\circ	ext{C}/	ext{m}. $$What is the freezing point (°C) of a solution of $$50.\ 	ext{g}$$ $$	ext{MgCl}_2 in$$ $$500.\ 	ext{g}$$ ethanol? (Assume complete dissociation.)

Accepted Answer

$$-120.9$$

Question 15

At a certain temperature, $$K_w = 5.13 	imes 10$$^{-13}$$. What is the pH of pure water at this temperature?

Accepted Answer

$$6.14$$

Question 16

Consider the reaction: $$	ext{N}_2 (g) + 3\ 	ext{H}_2 (g) ightleftharpoons 2\ 	ext{NH}_3 (g). At a $$certain temperature, $$0.500\ 	ext{atm}$$ $$	ext{N}_2$$ and $$1.00\ 	ext{atm}$$ $$	ext{H}_2$$ are allowed to come to equilibrium. At equilibrium, the partial pressure of $$	ext{NH}_3 is$$ $$0.00480\ 	ext{atm}. $$What is the value of $$K_p$$?

Accepted Answer

$$4.73 	imes 10$$^{-5}$$

Question 17

Calculate the concentration (M) of a $$	ext{Ba(OH)}_2$$ solution if $$0.65\ 	ext{L} of $$solution was required to reach the equivalence point of $$550\ 	ext{mL} of$$ $$0.64\ 	ext{M} HI.$$

Accepted Answer

$$0.27$$

Question 18

Which of the following best describes the triple point of a substance?

Accepted Answer

The temperature and pressure at which all three phases are in equilibrium

Question 19

Which of the following best explains why $$	ext{HF} in $$water has a higher boiling point than $$	ext{HCl} in $$water?

Accepted Answer

Hydrogen bonding between $$	ext{HF}$$ and water molecules

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