208- Among which compounds is it not possible to form hydrogen bonds?
(1) Vitamin C (2) Glycerin (3) Acetic acid (4) Trimethylamine

209- The bond angle in which molecule is closest to the bond angle in water?
(1) $CO_3^{2-}$ (2) $NH_3^-$ (3) $NO_3^+$ (4) $H_3O^+$

210- Which of the following statements are correct?

• [A)] The molecular formula of $\text{C}_{10}\text{H}_{16}\text{O}$ is correct.
• [B)] 2-heptanone and benzaldehyde have a carbonyl group and are isomers of each other.
• [C)] The name of the hydrocarbon with the dot-dash formula $\diagup\diagdown\diagup\diagdown$ is 3-methylnonane.
• [D)] The ratio of the number of H atoms to the number of C atoms in naphthalene molecules is 1.

(1) A, B (2) B, C (3) B, C, D (4) A, B, C, D

211- If three hydrogen molecules are removed from a cycloalkane molecule, which hydrocarbon is produced?
(1) Hexene (2) Benzene (3) Cyclohexene (4) Cyclohexadiene

212- In a reaction of a mixture of isotopes $^{16}\text{O}$ and $^{18}\text{O}$ with isotopes $^{25}\text{Mg}$ and $^{24}\text{Mg}$, how many acids can be formed with different molar masses? (Both elements have different molar masses; consider the highest capacity from your perspective. Assume the atomic mass of each element equals its mass number in $\text{g.mol}^{-1}$.)
(1) $1.075 \cdot 6$ (2) $1.025 \cdot 4$ (3) $1.075 \cdot 4$ (4) $1.025 \cdot 6$

213- If the hydroxyl group in aspirin replaces all the hydrogen groups, which substance is produced?
(1) Methyl salicylate (2) Benzaldehyde (3) Benzoic acid (4) Salicylic acid

214- What is the empirical formula of 3,5-dimethyloctane?
(1) $C_8H_{17}$ (2) $C_8H_{11}$ (3) $C_4H_9$ (4) $C_4H_8$

215- If 0.5 moles of aluminum sulfate are decomposed, producing 28.8 liters of gas at conditions where the molar volume of gases is 24 liters, what is the percent yield of the reaction and how many grams of solid product are obtained?
$(S = 32,\ Al = 27,\ O = 16\ \text{g.mol}^{-1})$
(1) $40.8 \cdot \Lambda\circ$ (2) $\Delta\circ/1 \cdot \Lambda\circ$ (3) $40.8 \cdot \Lambda\Delta$ (4) $\Delta\circ/1 \cdot \Lambda\Delta$

216- If 0.1 mol of $A_2(s)$ reacts with 1 mol of $X_2(s)$, according to the reaction: $$A_2(s) + X_2(s) \rightarrow 2AX(g),\quad \Delta E = -100\ \text{kJ},\quad \Delta H = -90\ \text{kJ}$$ When the reaction goes to completion, the approximate value of $\Delta V$ at a pressure of 1 atm at the end of the reaction and at the moment of return to the initial temperature, at STP conditions, how many liters to the left will it be?
$(1\text{atm} \approx 10^5\ \text{Pa})$
(1) $4.48 \cdot 10$ (2) $2.24 \cdot 10$ (3) $4.48 \cdot 100$ (4) $2.24 \cdot 100$
Calculation Space
%% Page 22 Chemistry 120-A Page 21

217- If the molar heat capacity of water and ethylene glycol are $\text{J.mol}^{-1}.\text{K}^{-1}$ equal to $75/4$ and $136/4$ respectively, and the temperature does not change by raising the pressure of five kilograms of the mixed solution of water and ethylene glycol inside a car engine to $1^\circ\text{C}$, approximately how many kilojoules of heat are required? (The mixture of water and ethylene glycol is $50\%$ by mass, $\text{O} = 16,\ \text{C} = 12,\ \text{H} = 1 : \text{g.mol}^{-1}$)
(1) $22/85$ (2) $20/94$ (3) $15/97$ (4) $10/47$

218- How many of the following statements are correct?

• In thermodynamics, by determining $\Delta G$, one can determine the feasibility of a reaction.
• In chemical kinetics, one can study how reactions proceed and the rate of reactions.
• The spontaneity of reactions, from a thermodynamic perspective, means that they have a high rate.
• Any reaction that is thermodynamically feasible has a suitable pathway (from a kinetics perspective) for it to occur.

(1) $1$ (2) $2$ (3) $3$ (4) $4$

219- The average bond enthalpy between two atoms given for which type of bond, compared to other proposed bonds, is greater?
(1) C and C in ethylene (2) O and O in $\text{O}_2$ (3) N and N in $\text{N}_2$ (4) C and C in cycloalkanes

220- To one liter of two molar sodium hydroxide solution, $200\ \text{mL}$ of water is continuously added every minute. How does the concentration of this solution change?
[Figure: Four graphs showing molar concentration vs. t(min): (1) concave decreasing curve, (2) convex decreasing curve, (3) linear decreasing, (4) concave decreasing curve (different shape)]

221- A mixture of water, toluene, table salt, and acetone, in terms of molar ratio, has how many phases?
(1) $1$ (2) $2$ (3) $3$ (4) $4$

222- From every liter of concentrated HCl solution with molality $1/2\ \text{g.mL}^{-1}$ and mass percent $36/5\%$, how many liters of hydrogen chloride gas are produced at STP conditions? $$(\text{Cl} = 35/5,\ \text{H} = 1 : \text{g.mol}^{-1})$$
(1) $22/4$ (2) $26/88$ (3) $224$ (4) $268/8$
\begin{flushright} Calculation space \end{flushright}
%% Page 23 Chemistry 120-A Page 22

223 – Which statement about a droplet of oil formed by non-ionic detergent molecules in water, when lipid enters water, is correct?

1. [(1)] The outer surface of the droplet has a negative charge.
2. [(2)] Sodium ions are distributed inside the fatty droplet.
3. [(3)] The lipid is of the gel type, and water is the dispersing phase in it.
4. [(4)] It remains stationary in water and settles spontaneously.

224 – If the progress graph of the decomposition reaction of hydrogen peroxide is as shown below, which of the following graphs approximately shows the change in the amount of oxygen in this reaction?
[Figure: Graph showing amount of substance (mol) on y-axis from 0.10 to 1.00, with values marked at approximately 0.74, 0.54, 0.40, 0.33, 0.27, 0.22, 0.18 at time intervals on x-axis (time in seconds) from 0 to 80. The curve is a decreasing exponential.]

\begin{minipage}{0.45\textwidth} \centering [Figure (2): Graph with mol on y-axis (0 to 1, marked at 0.5), time (seconds) on x-axis (20, 40, 60, 80). Curve starts near 0 and increases, leveling off around 0.5.] \end{minipage}	\begin{minipage}{0.45\textwidth} \centering [Figure (1): Graph with mol on y-axis (0 to 1, marked at 0.5), time (seconds) on x-axis (20, 40, 60, 80). Curve starts near 0 and increases steeply, approaching 1.] \end{minipage}
[2em] \begin{minipage}{0.45\textwidth} \centering [Figure (4): Graph with mol on y-axis (0 to 1, marked at 0.5), time (seconds) on x-axis (20, 40, 60, 80). Curve starts near 0 and increases linearly.] \end{minipage}	\begin{minipage}{0.45\textwidth} \centering [Figure (3): Graph with mol on y-axis (0 to 1, marked at 0.5), time (seconds) on x-axis (20, 40, 60, 80). Curve starts near 0 and increases, concave upward.] \end{minipage}

%% Page 24 Chemistry 120-A Page 23

225. In a city with 1,000,000 cars, and each car travels an average of 10,000 kilometers per year, using a catalytic converter reduces the percentage of several pollutants produced and the amount of pollutants after using the catalytic converter in one year will be how many tons? (Read the options from right to left.)

NO	$C_xM_y$	CO		Pollutant
$1/\circ f$	$1/\mathit{6}V$	$\mathit{6}$	Without converter	Amount of pollutant per kilometer
$\circ/\circ f$	$\circ/\circ V$	$\circ/\mathit{6}$	With converter	grams per kilometer

(1) $Y1\circ\circ \cdot \Lambda\Delta$ (2) $Y\Delta\circ\circ \cdot \Lambda\Delta$ (3) $Y1\circ\circ \cdot 9Y$ (4) $Y\Delta\circ\circ \cdot 9Y$

226. Considering the reaction: $\mathrm{NiO(s) + CO(g) \rightleftharpoons Ni(s) + CO_2(g)}$, $\Delta H < 0$, which is at equilibrium at a certain temperature, which of the following statements are correct?

• The equilibrium constant expression is: $K = \dfrac{[\mathrm{CO_2}]}{[\mathrm{CO}]}$
• By decreasing temperature, the equilibrium shifts to establish a larger $K$.
• By removing some $\mathrm{Ni(s)}$ from the reaction system, the equilibrium shifts in the forward direction.
• By moving to a smaller volume (at constant temperature), the equilibrium establishes a smaller $K$.

(1) 1 (2) 2 (3) 3 (4) 4

227. 1 mole of ozone gas is placed in a 1-liter flask and allowed to reach equilibrium: $\mathrm{3O_2(g) \rightleftharpoons 2O_3(g)}$, grams. If at the moment of equilibrium, the molar concentration of ozone gas is $\dfrac{1}{6}$ of the molar concentration of oxygen gas, what is the equilibrium constant of this reaction?
(1) $fY/Y\ \mathrm{L.mol^{-1}}$ (2) $fY/Y\ \mathrm{mol.L^{-1}}$ (3) $\circ/\mathit{6}\ \mathrm{L.mol^{-1}}$ (4) $\circ/\mathit{6}\ \mathrm{mol.L^{-1}}$

228. In the reaction of 6 moles of $\mathrm{NO}$ gas with 4 moles of $\mathrm{CO}$ gas in a closed 2-liter flask at a certain temperature, 42 g of nitrogen gas is present at equilibrium, $K = \mathrm{L.mol^{-1}}$ and the total number of moles of gas in the reaction flask, from right to left, is which of the following? $(N = 14\ \mathrm{g.mol^{-1}})$
(1) $f/Y\Delta \cdot Y$ (2) $\Lambda/\Delta \cdot Y$ (3) $f/Y\Delta \cdot 1/\Delta$ (4) $\Lambda/\Delta \cdot 1/\Delta$

229. The concentration of sulfur in a gasoline sample is 6400 ppm. Assuming complete combustion of sulfur in the engine and conversion to sulfuric acid gas, burning one kilogram of this gasoline can lower the pH of 1000 liters of pure water in a tank by approximately how many units? (Under experimental conditions, assume both ionization steps of the acid are complete.)
$$(S = rr,\ O = 1\mathit{6},\ H = 1:\ \mathrm{g.mol^{-1}})$$
(1) $r/\mathit{6}$ (2) $\mathit{6}/Y$ (3) $r$ (4) $f$
\rule{0.8\textwidth}{0.4pt} Calculation Space
%% Page 25 Chemistry 120-A Page 24

230 -- If the value of $\alpha$ for acid HA is equal to $10\%$, the pH of its solution is 3, and the value of $K_a$ is equal to $\text{mol.L}^{-1}$, approximately:
\begin{align*} &(1) 1/11\times10^{-6}\ ,\ 9\times10^{-3} (2) 1/11\times10^{-6}\ ,\ 1\times10^{-2} &(3) 1/11\times10^{-4}\ ,\ 9\times10^{-3} (4) 1/11\times10^{-4}\ ,\ 1\times10^{-2} \end{align*}

231 -- If the molar ratio of hydronium ions to hydroxide ions in a strong base solution is $10^{10}$, how many moles of HCl are needed to neutralize 100 mL of this solution?
$$ (1)\quad 10^{-2} \qquad (2)\quad 5\times10^{-2} \qquad (3)\quad 10^{-3} \qquad (4)\quad 5\times10^{-3} $$

232 -- By adding 1 milliliter of a 10 molar hydrochloric acid solution to 1 liter of pure water, the approximate concentration of the resulting solution in ppm and the color of methyl red in this solution are:
$$(\text{HCl} = 36/5\ \text{g.mol}^{-1}\ \text{ and }\ d_{\text{solution}} = 1\ \text{g.mL}^{-1})$$
\begin{align*} &(1) 365,\ \text{yellow} (2) 365,\ \text{red} (3) 36/5,\ \text{yellow} (4) 36/5,\ \text{red} \end{align*}