$$ \frac{10}{100} \times 100 = 10\% $$

$$ V_1$ = \frac{M_2$ \times V_2$}{M_1$} = \frac{1.0 \times 1.0}{5.0} = 0.2\,L $$

Question 1

Which of the following best describes a solution?

Accepted Answer

A homogeneous mixture of two or more substances where one is dissolved in the other.

Question 2

Water is often referred to as the 'universal solvent.' Which property of water makes it effective at dissolving many ionic and polar substances?

Accepted Answer

Water is polar, enabling it to interact with charged and polar solutes.

Question 3

Which type of intermolecular force is primarily responsible for the solubility of ionic compounds in water?

Accepted Answer

Ion-dipole interactions

Question 4

A student is given a sample of sodium chloride (NaCl) and hexane (C6H14). Which solvent would best dissolve NaCl, and why?

Accepted Answer

Water, because it is polar and forms ion-dipole interactions with NaCl.

Question 5

Which statement about solubility is correct?

Accepted Answer

Solubility is the maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature.

Question 6

How does increasing temperature affect the solubility of a solid and a gas in water?

Accepted Answer

Solubility of solids increases, but solubility of gases decreases with temperature.

Question 7

According to Henry’s Law, what happens to the solubility of a gas in a liquid when the pressure above the liquid increases?

Accepted Answer

The solubility of the gas increases.

Question 8

A solution is prepared by dissolving 10 g of glucose in 90 g of water. What is the mass percent (m/m) of glucose in the solution?

Accepted Answer

$$ \frac{10}{100} 	imes 100 = 10\% $$

Question 9

What is the molarity ($$M) of a $$solution made by dissolving 0.5 mol of NaCl in enough water to make 2.0 L of solution?

Accepted Answer

$$ M = \frac{0.5}{2.0} = 0.25\,M $$

Question 10

A nurse needs to dilute a 5.0 M stock solution of KCl to make 1.0 L of a 1.0 M solution. How much of the stock solution should be used?

Accepted Answer

$$ V_1$ = \frac{M_2$ 	imes V_2$}{M_1$} = \frac{1.0 	imes 1.0}{5.0} = 0.2\,L $$

Question 11

Which of the following is a strong electrolyte?

Accepted Answer

Sodium chloride (NaCl)

Question 12

Which colligative property explains why adding salt to water increases its boiling point?

Accepted Answer

Boiling point elevation

Question 13

A red blood cell is placed in a hypotonic solution. What will happen to the cell?

Accepted Answer

The cell will swell and may burst as water enters the cell.

Question 14

Which of the following statements about activation energy is correct?

Accepted Answer

Activation energy is the energy required to start a chemical reaction.

Question 15

How does a catalyst affect the rate of a chemical reaction?

Accepted Answer

It decreases the activation energy, speeding up the reaction.

Question 16

Which of the following is a reversible chemical reaction?

Accepted Answer

$$ \mathrm{N_2$} + 3\mathrm{H_2$} \rightleftharpoons 2\mathrm{NH_3$} $$

Question 17

Write the equilibrium expression for the reaction $$ aA + bB \rightleftharpoons cC + dD .$$

Accepted Answer

$$ K_c = \frac{[C]^c [D]^d}{[A]^a [B]^b} $$

Question 18

If a reaction has a very large equilibrium constant ($$K_c \gg 1$$), what does this indicate about the reaction at equilibrium?

Accepted Answer

The reaction favors the products at equilibrium.

Question 19

According to Le Châtelier’s principle, what happens to the equilibrium position if more reactant is added to a system at equilibrium?

Accepted Answer

The equilibrium shifts toward the products.

Guided Study for Solutions, Equilibrium, and Acids/Bases (GOB Chemistry)

Guida di studio - Domande di pratica