Part I. (8 points) Multiple choice questions

Question 1: Classify the following reaction:
$\text{Na (s)} + \text{H}_2\text{O (l)} \rightarrow \text{NaOH (aq)} + \text{H}_2 \text{(g)}$

• A. Neutralization reaction
• B. Redox reaction
• C. Single replacement reaction
• D. Double replacement reaction

Question 2: Assign the oxidation numbers of the elements on the product side
$\text{H}_2\text{O}_2 \text{(l)} \rightarrow \text{H}_2\text{O (l)} + \text{O}_2 \text{(g)}$

• A. -1, 0, 1
• B. +1, -1, 0
• C. +1, -2, 0
• D. +1, -1, -2

Question 3: When gold dissolves in aqua regia (a mixture of nitric acid and hydrochloric acid), what is reduced?
$\text{Au} + 3\text{NO}_3^- + 4\text{Cl}^- + 6\text{H}^+ \rightarrow \text{AuCl}_4^- + 3\text{NO}_2 + 3\text{H}_2\text{O}$

• A. $\text{H}^+$
• B. $\text{N}^{5+}$
• C. $\text{Cl}^-$
• D. $\text{Au}$

Question 4: What are the respective molarities of sodium and sulfate ions afforded by dissolving 0.500 mol $\text{Na}_2\text{SO}_4$ in water and diluting to 1.33 L?

• A. 0.542 M and 0.271 M
• B. 1.34 M and 2.68 M
• C. 0.752 M and 0.376 M
• D. 0.338 M and 0.676 M

Part II. (2 points) Long answer question

Question 5: What is the molarity of $\text{CH}_3\text{OH}$ in a solution prepared by dissolving 11.7 g of $\text{CH}_3\text{OH}$ in sufficient water to give exactly 230 mL of solution? Give an explanation for your answer.