Q: Calculate the osmotic pressure ($$\Pi) at 25$^\circC $$for a 0.10 M NaCl solution, assuming complete dissociation. ($$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$}$$, $$T = 298\ \mathrm{K})$$

$$\Pi = 0.20 \times 0.0821 \times 298$$

Question 1

Which of the following solute-solvent combinations would most likely result in a solution, based on the principle 'like dissolves like'?

Accepted Answer

A polar solute in a polar solvent

Question 2

Which intermolecular force is primarily responsible for the solubility of NaCl in water?

Accepted Answer

Ion-dipole interactions

Question 3

A solution is prepared by dissolving 0.5 mol of glucose (C$$_6H$_{12}O$_6) in $$enough water to make 1.0 L of solution. What is the molarity (M) of glucose in the solution?

Accepted Answer

$$0.5\ \mathrm{M}$$

Question 4

Which of the following statements about ideal solutions is TRUE?

Accepted Answer

Solute-solvent interactions are similar in strength to solute-solute and solvent-solvent interactions.

Question 5

Which equation is used to calculate the vapor pressure of an ideal solution using Raoult's Law?

Accepted Answer

$$P_{solution} = X_A P_A^* + X_B P_B^*$$

Question 6

A saturated solution of KNO$$_3 at 60$^\circC $$contains 110 g of KNO$$_3$$ per 100 g of water. What will happen if the solution is cooled to 30$$^\circC$$, where the solubility is 50 g per 100 g water?

Accepted Answer

Excess KNO$$_3$$ will precipitate out until the solution reaches the new solubility.

Question 7

Which colligative property is responsible for the lowering of the freezing point when salt is added to ice?

Accepted Answer

Freezing point depression

Question 8

Calculate the osmotic pressure ($$\Pi) at 25$^\circC $$for a 0.10 M NaCl solution, assuming complete dissociation. ($$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$}$$, $$T = 298\ \mathrm{K})$$

Accepted Answer

$$\Pi = 0.20 	imes 0.0821 	imes 298$$

Question 9

Which of the following best describes the effect of temperature on the solubility of gases in liquids?

Accepted Answer

Solubility decreases with increasing temperature.

Question 10

A solution contains 0.2 mol of Na$$_2SO$_4$$ dissolved in 1.0 L of water. What is the total concentration of ions in the solution?

Accepted Answer

$$0.6\ \mathrm{mol/L}$$

Question 11

Which of the following is the correct integrated rate law for a first-order reaction?

Accepted Answer

$$\ln [A]_t = -kt + \ln [A]_0$$

Question 12

The half-life of a first-order reaction is given by which equation?

Accepted Answer

$$t_{1/2} = \frac{0.693}{k}$$

Question 13

Which factor does NOT affect the rate constant ($$k) in $$the Arrhenius equation?

Accepted Answer

Concentration of reactants

Question 14

Given the reaction: 2A + B $$ightarrow C$$, the rate law is found to be $$	ext{rate} = k[A]^2[B]. $$What is the overall order of the reaction?

Accepted Answer

Third order

Question 15

Which statement about reaction mechanisms is TRUE?

Accepted Answer

Intermediates are produced and consumed during the reaction but do not appear in the overall equation.

Question 16

Which of the following is the correct form of the Arrhenius equation?

Accepted Answer

$$k = Ae$$^{-E_a/RT}$$

Question 17

A reaction has a rate constant $$k = 0.25\ \mathrm{min}^{-1} at 25$^\circC. $$What is the half-life of the reaction?

Accepted Answer

$$2.77\ \mathrm{min}$$

Question 18

Which statement best describes the effect of a catalyst on a chemical reaction?

Accepted Answer

It decreases the activation energy and increases the reaction rate.

Question 19

For a second-order reaction, which plot yields a straight line?

Accepted Answer

$$1/[A] vs. $$time

General Chemistry Study Guide: Solutions and Kinetics

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