Question 1

Which of the following best defines Avogadro's Number?

Accepted Answer

The number of particles in exactly 12 grams of carbon-12, which is $$6.022 	imes 10$$^{23}$$.

Question 2

Which of the following is the correct set of coefficients to balance the equation: $$\mathrm{NH_3$ + O_2$ \rightarrow NO + H_2O}$$?

Accepted Answer

4, 5, 4, 6

Question 3

A solution is best described as:

Accepted Answer

A homogeneous mixture where the solute is evenly dispersed in the solvent.

Question 4

Why does sodium chloride (NaCl) dissolve in water?

Accepted Answer

Because the electrostatic attractions between water molecules and Na$$^+$$ and Cl$$^-$$ ions overcome the attractions between the ions themselves.

Question 5

Which of the following statements about the dissolution of ionic compounds in water is correct?

Accepted Answer

Ionic compounds dissociate into ions, which are then surrounded by water molecules.

Question 6

Which of the following best explains why ionic solutions conduct electricity?

Accepted Answer

Because the ions are free to move and carry charge through the solution.

Question 7

Given the solubility data: solubility of NaCl in H$$_2O at 20$^\circC is 365 g/L$$, and solubility of AgCl in H$$_2O at 20$^\circC is 0.009 g/L. $$Which statement is correct?

Accepted Answer

NaCl is much more soluble in water than AgCl.

Question 8

Which image best represents a mixture of BaCl$$_2$$ and water?

Accepted Answer

An image showing Ba$$^{2+}$$ and Cl$$^-$$ ions evenly dispersed in water.

Question 9

Which of the following best describes a precipitation reaction?

Accepted Answer

A reaction in which a solid forms from the mixing of two solutions due to the formation of an insoluble product.

Question 10

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

Accepted Answer

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

Question 11

Which of the following best describes the role of water's polarity in dissolving ionic compounds?

Accepted Answer

Water's polarity allows it to form hydration complexes with ions, stabilizing them in solution.

Question 12

Which of the following is true about the dissolution of sugar (a molecular compound) in water?

Accepted Answer

Sugar molecules remain intact and are surrounded by water molecules.

Question 13

Which of the following is the best definition of dissociation in the context of aqueous solutions?

Accepted Answer

The process of separating cations and anions by water, resulting in free ions in solution.

Question 14

Which of the following statements is correct regarding electrolytes?

Accepted Answer

Electrolytes are substances that conduct electricity when dissolved in water because they produce ions.

Question 15

A student mixes aqueous solutions of potassium iodide and lead(II) nitrate. A yellow solid forms. What type of reaction has occurred?

Accepted Answer

A precipitation reaction, forming PbI$$_2 as a $$solid.

Question 16

Which of the following best explains why AgCl does not dissolve in water, while NaCl does?

Accepted Answer

The electrostatic attractions between Ag$$^+$$ and Cl$$^- in $$AgCl are much stronger than the attractions between Na$$^+$$ and Cl$$^- in $$NaCl.

Study Guide: Chemical Reactions and Solutions in Introductory Chemistry

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