Chapter 2

20.0 \(\mathrm{mL}\) of 1.0 \(\mathrm{M} \mathrm{Na}_{2} \mathrm{CO}_{3}\) is placed in a beaker and titrated with a solution of \(1.0 \mathrm{M} \mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2},\) resulting in the creation of a precipitate. If the experiment were repeated and the \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) was diluted to 40.0 \(\mathrm{mL}\) with distilled water prior to the titration, how would that affect the volume of \(\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}\) needed to reach the equivalence point? (A) It would be cut in half. (B) It would decrease by a factor of 1.5. (C) It would double. (D) It would not change.

\(2 \mathrm{CO}(g)+\mathrm{O}_{2}(g) \rightarrow 2 \mathrm{CO}_{2}(g)\) 2.0 mol of \(\mathrm{CO}(g)\) and 2.0 mol of \(\mathrm{O}_{2}(g)\) are pumped into a rigid, evacuated \(4.0-\mathrm{L}\) container, where they react to form \(\mathrm{CO}_{2}(g) .\) Which of the following values does NOT represent a potential set of concentrations for each gas at a given point during the reaction? (A) 0.5 0.5 0 (B) 0 0.25 0.5 (C) 0.25 0.25 0.5 (D) 0.25 0.38 0.25

Neutral atoms of chlorine are bombarded by high-energy photons, causing the ejection of electrons from the various filled subshells. Electrons originally from which subshell would have the highest velocity after being ejected? (A) 1s (B) 2p (C) 3p (D) 3d

A sample of oxygen gas at \(50^{\circ} \mathrm{C}\) is heated, reaching a final temperature of \(100^{\circ} \mathrm{C} .\) Which statement best describes the behavior of the gas molecules? (A) Their velocity increases by a factor of two. (B) Their velocity increases by a factor of four. (C) Their kinetic energy increases by a factor of 2. (D) Their kinetic energy increases by a factor of less than 2.

The average mass, in grams, of one mole of carbon atoms is equal to (A) the average mass of a single carbon atom, measured in amus (B) the ratio of the number of carbon atoms to the mass of a single carbon atom (C) the number of carbon atoms in one amu of carbon (D) the mass, in grams, of the most abundant isotope of carbon

Which of the following is true for all bases? (A) All bases donate \(\mathrm{OH}^{-}\) ions into solution. (B) Only strong bases create solutions in which \(\mathrm{OH}^{-}\) ions are present. (C) Only strong bases are good conductors when dissolved in solution. (D) For weak bases, the concentration of the \(\mathrm{OH}^{-}\) ions exceeds the concentration of the base in the solution.

\(14 \mathrm{H}^{+}(a q)+\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q)+3 \mathrm{Ni}(s) \rightarrow\) \(2 \mathrm{Cr}^{3+}(a q)+3 \mathrm{Ni}^{2+}(a q)+7 \mathrm{H}_{2} \mathrm{O}(l)\) In the above reaction, a piece of solid nickel is added to a solution of potassium dichromate. Which species is being oxidized and which is being reduced? \(\quad\) Oxidized \(\quad\) Reduced (A) \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q) \quad \mathrm{Ni}(s)\) (B) \(\mathrm{Cr}^{3+}(a q) \quad \mathrm{Ni}^{2+}(a q)\) (C) \(\mathrm{Ni}(s) \quad \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q)\) (D) \(\mathrm{Ni}^{2+}(a q) \quad \mathrm{Cr}^{3+}(a q)\)

The bond length between any two nonmetal atoms is achieved under which of the following conditions? (A) Where the energy of interaction between the atoms is at its minimum value (B) Where the nuclei of each atom exhibits the strongest attraction to the electrons of the other atom (C) The point at which the attractive and repulsive forces between the two atoms are equal (D) The closest point at which a valence electron from one atom can transfer to the other atom

Hydrogen fluoride, HF, is a liquid at \(15^{\circ} \mathrm{C}\) . All other hydrogen halides (represented by HX, where \(\mathrm{X}\) is any other halogen) are gases at the same temperature. Why? (A) Fluorine has a very high electronegativity; therefore, the H–F bond is stronger than any other H–X bond. (B) HF is smaller than any other H–X molecule; therefore, it exhibits stronger London dispersion forces. (C) The dipoles in a HF molecule exhibit a particularly strong attraction force to the dipoles in other HF molecules. (D) The H–F bond is the most ionic in character compared to all other hydrogen halides.

$$\begin{array}{|c|c|c|}\hline & {\text { Initial pH }} & {\text { PH after NaOH }} \\ \hline \text { Acid 1 } & {3.0} & {3.5} \\ \hline \text { Acid 2 } & {3.0} & {5.0} \\ \hline\end{array}$$ Two different acids with identical pH are placed in separate beakers. Identical portions of NaOH are added to each beaker, and the resulting pH is indicated in the table above. What can be determined about the strength of each acid? (A) Acid 1 is a strong acid and acid 2 is a weak acid because acid 1 resists change in pH more effectively. (B) Acid 1 is a strong acid and acid 2 is a weak acid because the NaOH is more effective at neutralizing acid 2. (C) Acid 1 is a weak acid and acid 2 is a strong acid because the concentration of the weak acid must be significantly greater to have the same pH as the strong acid. (D) Acid 1 is a weak acid and acid 2 is a strong acid because the concentration of the hydrogen ions will be greater in acid 2 after the NaOH addition.