Q: A solution has a pH of 3. What is the concentration of $$\mathrm{H^+}$$ ions?

$$1 \times 10$$^{-3}$$\ \mathrm{M}$$

Question 1

Which of the following best describes a chemical reaction at equilibrium?

Accepted Answer

The forward and reverse reaction rates are equal.

Question 2

A reaction has an activation energy of $$50\ \mathrm{kJ/mol}. If $$the temperature is increased, what happens to the rate of reaction?

Accepted Answer

The rate increases because more molecules have enough energy to overcome the activation barrier.

Question 3

Which of the following is NOT a characteristic of gases according to the kinetic molecular theory?

Accepted Answer

Gas particles experience strong intermolecular forces.

Question 4

A solution is prepared by dissolving $$10\ \mathrm{g} of $$NaCl in $$100\ \mathrm{g} of $$water. What is the mass percent of NaCl in the solution?

Accepted Answer

$$10\%$$

Question 5

Which of the following statements about acids and bases is correct according to the Brønsted-Lowry theory?

Accepted Answer

An acid is a substance that donates a proton ($$\mathrm{H^+}).$$

Question 6

If the equilibrium constant $$K$$ for a reaction is much greater than 1, what does this indicate about the reaction?

Accepted Answer

Products are favored at equilibrium.

Question 7

Which of the following will increase the rate of a chemical reaction?

Accepted Answer

Adding a catalyst.

Question 8

A buffer solution is best described as:

Accepted Answer

A solution that resists changes in pH when small amounts of acid or base are added.

Question 9

Which equation correctly represents the relationship between pressure, volume, and temperature for an ideal gas?

Accepted Answer

$$P = \dfrac{nRT}{V}$$

Question 10

A reaction is exothermic. Which of the following is true?

Accepted Answer

The system releases heat to the surroundings.

Question 11

Which intermolecular force is strongest in water ($$\mathrm{H_2O}$$)?

Accepted Answer

Hydrogen bonding

Question 12

If $$0.5\ \mathrm{mol} of$$ $$\mathrm{CO_2$}$$ gas is placed in a $$2.0\ \mathrm{L}$$ container at $$25^\circ\mathrm{C}$$, what is the pressure in the container? (Use $$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$})$$

Accepted Answer

$$6.1\ \mathrm{atm}$$

Question 13

Which of the following will NOT affect the position of equilibrium in a chemical reaction?

Accepted Answer

Adding a catalyst.

Question 14

A solution has a pH of 3. What is the concentration of $$\mathrm{H^+}$$ ions?

Accepted Answer

$$1 	imes 10$$^{-3}$$\ \mathrm{M}$$

Question 15

Which of the following is a colligative property of solutions?

Accepted Answer

Boiling point elevation

Question 16

Which of the following reactions is a redox reaction?

Accepted Answer

$$2\mathrm{Na} + 2\mathrm{H_2O} \rightarrow 2\mathrm{NaOH} + \mathrm{H_2$}$$

Question 17

Which statement best explains why ice floats on water?

Accepted Answer

Ice is less dense than liquid water because its molecules are arranged in an open lattice structure.

Question 18

Which of the following is true about strong acids?

Accepted Answer

They completely dissociate in water.

Question 19

A chemical reaction has $$\Delta G \u003c 0. $$What does this indicate?

Accepted Answer

The reaction is spontaneous.

Question 20

Which of the following will increase the solubility of a gas in a liquid?

Accepted Answer

Increasing the pressure.

General Chemistry: Key Topics Overview (Chemical Reactions, Energy, Gases, Solutions, Acids & Bases)

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