Chemistry Questions & Answers

For the reaction, \( \mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \longrightarrow 2 \mathrm{NH}_{3}(\mathrm{~g}) \), the free energy changes at \( 25^{\circ} \mathrm{C} \) and \( 35^{\circ} \mathrm{C} \) are -3.98 and -3.37 Kcal respectively. Calculate the heat of reaction at \( 35^{\circ} \mathrm{C} \).

\( HCl + Ca ( OH ) _ { 2 } \rightarrow CaCl _ { 2 } + H _ { 2 } O \)

What does stoichiometry use to relate moles of one molecule to moles of another? A. Atomic number ratios B. Coefficient ratios C. Oxidation state ratios D. Subscript ratios

What important discovery did Ernest Rutherford make? A. He found that the atom contained both protons and electrons. B. He found that light could make electrons flow in metals. C. He found that the atom was made up of mostly empty space. D. He found that electrons were negatively charged particles.

How is molarity measured? A. In moles of a substance dissolved in 1 L of water B. In moles of a substance for 1 g of that substance C. In liters of water per gram of a dissolved substance D. In liters of water per moles of a dissolved substance

What are the half-reactions for an electrolytic cell with aluminum and gold electrodes? \[ \begin{array}{l}\text { A. } \mathrm{Al}(s) \rightarrow \mathrm{Al}^{3+}(a q)+3 e^{-} \text {and } \mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \rightarrow \mathrm{Au}(s) \\ \text { B. } \mathrm{Al}^{3+}(a q)+3 \mathrm{e}^{-} \rightarrow \mathrm{Al}(s) \text { and } \mathrm{Au}(s) \rightarrow \mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \\ \text {C. } \mathrm{Al}^{3+}(a q)+3 \mathrm{e}^{-} \rightarrow \mathrm{Al}(s) \text { and } \mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \rightarrow \mathrm{Au}(s) \\ \text { D. } \mathrm{Al}^{-}(s) \rightarrow \mathrm{Al}^{3+}(a q)+3 \mathrm{e}^{-} \text {and } \mathrm{Au}(s) \rightarrow \mathrm{Au}^{+}(a q)+\mathrm{e}^{-}\end{array} \]

What are the half-reactions for a galvanic cell with aluminum and gold electrodes? \[ \begin{array}{l}\text { A. } \mathrm{Al}^{3+}(a q)+3 \mathrm{e}^{-} \rightarrow \mathrm{Al}(s) \text { and } \mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \rightarrow \mathrm{Au}(s) \\ \text { B. } \mathrm{Al}^{-}(s) \rightarrow \mathrm{Al}^{3+}(a q)+3 e^{-} \text {and } \mathrm{Au}(s) \rightarrow \mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \\ \text {C. } \mathrm{Al}^{3+}(a q)+3 \mathrm{e}^{-} \rightarrow \mathrm{Al}(s) \text { and } \mathrm{Au}(s) \rightarrow \mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \\ \text {D. } \mathrm{Al}^{-}(s) \rightarrow \mathrm{Al}^{3+}(a q)+3 \mathrm{e}^{-} \text {and } \mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \rightarrow \mathrm{Au}(s)\end{array} \]

Which of the following describes a liquid? A. Does not have a fixed volume or a fixed shape B. Has a fixed volume and a fixed shape C. Has a fixed shape but not a fixed volume D. Has a fixed volume but not a fixed shape

Which of the following contains a polar covalent bond? \[ \begin{array}{l}\text { A. } \mathrm{Na}(s) \\ \text { B. } \mathrm{O}_{2} \\ \text { C. } \mathrm{NaCl} \\ \text { D. } \mathrm{NO}\end{array} \]

What is the correct name for \( \mathrm{Na}_{2} \mathrm{O} \) ? \( \begin{array}{l}\text { A. Sodium(II) oxide } \\ \text { B. Disodium oxide } \\ \text { C. Sodium dioxide } \\ \text { D. Sodium oxide }\end{array} \)