198. Inside two containers with equal volumes, there are $n$ moles of oxygen gas and the same number of moles of helium gas respectively. During an isobaric process, we give equal amounts of heat to both gases. If we denote the ratio of the increase in temperature of helium to the increase in temperature of oxygen by $k$, and the ratio of the change in internal energy of helium to the change in internal energy of oxygen by $m$, which option is correct?
\[ (1)\quad m=1,\ k>1 \qquad (2)\quad m=1,\ k=1 \qquad (3)\quad m<1,\ k<1 \qquad (4)\quad m>1,\ k>1 \]

199. A temperature of $122$ degrees Fahrenheit equals how many degrees Celsius and how many Kelvin?
\[ (1)\quad 50 \text{ and } 323 \qquad (2)\quad 50 \text{ and } 323 \qquad (3)\quad 59 \text{ and } 332 \qquad (4)\quad 59 \text{ and } 323 \]

200. The melting point of gold:
(1) Decreases greatly at the nanoscale of particles.
(2) Increases greatly at the nanoscale of particles.
(3) Both the nanoscale particle and the nanoscale layer decrease greatly.
(4) Both the nanoscale particle and the nanoscale layer increase greatly.
Space for Calculations
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201. Which of the following statements are correct?

• [A)] Generally, the higher the reactivity of a metal, the more difficult its extraction.
• [B)] The reactivity of each element means its tendency to undergo a chemical reaction.
• [C)] In the reaction: $\text{FeO(s)}$ with $\text{Na(s)}$, the reactivity of the reactants is greater than that of the products.
• [D)] In the reaction: $\text{Na}_2\text{O(s)}$ with $\text{C(s)}$, the reactivity of the reactants is greater than that of the products.

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

202. In the third period of the periodic table, the number of metallic and non-metallic elements from right to left, respectively, are (ignoring noble gases):
(1) 4, 3 (2) 3, 4 (3) 4, 3 (4) 3, 4

203. The overall trend of reactivity of the first four elements from the left of the second period of the periodic table (alternating) against oxygen at room temperature is which of the following? Their group numbers in order are:
[Figure: Four graphs showing reactivity vs. group number (1, 2, 13, 14) with different zigzag patterns labeled (1), (2), (3), (4)]

204. The electronic configuration of the last shell of which element is similar to the electronic configuration of the last shell of atom $\text{K}_{19}$?
(1) $_{29}\text{A}$ (2) $_{31}\text{D}$ (3) $_{37}\text{X}$ (4) $_{31}\text{Z}$

205. Hypothetical element $X$ has two isotopes with masses $14\,\text{amu}$ and $16\,\text{amu}$, and an average atomic mass of $14.2\,\text{amu}$. The ratio of the number of atoms of the lighter isotope to the heavier isotope is:
$$ (1)\ \dfrac{1}{8} \hfill (2)\ \dfrac{1}{9} \hfill (3)\ \dfrac{1}{10} \hfill (4)\ \dfrac{1}{11} $$

206. The sum of the stoichiometric coefficients of the substances in the reaction: $$\text{Na}_2\text{O}_2\text{(s)} + \text{H}_2\text{O(l)} \rightarrow \text{NaOH(aq)} + \text{O}_2\text{(g)}$$ after balancing, is:
(1) 8 (2) 9 (3) 10 (4) 11
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207. If 5 grams of $\text{LiAlH}_4(\text{s})$ reacts with water, according to the equation for $\text{Li}$, $11/2\,\text{L}$ of gas is produced at STP conditions, what is the purity percentage of $\text{LiAlH}_4(\text{s})$? $(\text{Al}=27,\ \text{Li}=7,\ \text{H}=1:\text{g.mol}^{-1})$
$$\text{LiAlH}_4(\text{s})+\text{H}_2\text{O}(\text{l})\rightarrow \text{LiOH}(\text{aq})+\text{Al(OH)}_3(\text{s})+\text{H}_2(\text{g}) \quad \text{(equation to be balanced)}$$
(1) $80$ (2) $85$ (3) $90$ (4) $95$

208. 20 grams from a sample of iron ore mineral is placed into 100 milliliters of acid solution so that $\text{Fe}^{3+}$ ions are dissolved in it. The solution is then treated by adding 5.35 grams of $\text{NaOH}(\text{s})$ to the solution; if iron(III) hydroxide is obtained, what is the percentage of iron in this ore sample? (equations to be balanced)
$$(\text{Fe}=56,\ \text{O}=16,\ \text{H}=1:\text{g.mol}^{-1})$$
$$\text{Fe}_2\text{O}_3(\text{s})+\text{HCl}(\text{aq})\rightarrow \text{FeCl}_3(\text{aq})+\text{H}_2\text{O}(\text{l})$$ $$\text{FeCl}_3(\text{aq})+\text{NaOH}(\text{aq})\rightarrow \text{Fe(OH)}_3(\text{s})+\text{NaCl}(\text{aq})$$
(1) $4$ (2) $8$ (3) $10$ (4) $14$

209. Trees by absorbing $\text{CO}_2(\text{g})$ can convert it to glucose ($\text{C}_6\text{H}_{12}\text{O}_6$). If a tree absorbs 660 kg of $\text{CO}_2$ gas per year, how many kilograms of sugar are produced in it?
$$(\text{O}=16,\ \text{C}=12,\ \text{H}=1:\text{g.mol}^{-1}\ ;\ \text{CO}_2(\text{g})+\text{H}_2\text{O}(\text{l})\rightarrow \text{C}_6\text{H}_{12}\text{O}_6(\text{aq})+\text{O}_2(\text{g}) \quad \text{(equation to be balanced)})$$
(1) $450$ (2) $250$ (3) $180$ (4) $210$

210. How many of the following statements are correct?

• Argon gas is the third most abundant gas in the air.
• The distillation apparatus was invented by Jabir ibn Hayyan.
• Some animals use atmospheric nitrogen for consumption by plants in the soil, for fixation.
• The proportion of noble gases in the air has remained approximately constant for about 200 million years.

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

211. Referring to the figure below, how many of the following statements about salt $\text{MX}$ are correct?

• At point B, the solution of this salt is saturated.
• Point A shows the dissolution of this salt at $0^\circ\text{C}$.
• At point D, the solvent can dissolve more of this salt.
• At point C, the solvent has been able to dissolve more than the saturation limit of this salt.

[Figure: Solubility curve of salt MX; x-axis: temperature ($^\circ$C) from 0 to 80; y-axis: solubility; curve passes through points A (at 0), B, C, D marked on and around the curve.]
(1) $1$ (2) $2$ (3) $3$ (4) $4$
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212. Which of the following processes related to osmosis is not related to the property of osmosis?

• [(1)] Fresh cucumber wilting in saltwater
• [(2)] Swelling of dry gelatin inside a balloon
• [(3)] Settling of mud and clay at the bottom of the sea
• [(4)] Long-term preservation of meat and fish in salt

213. A solution of 23\% by mass ethanol in water, approximately how many moles per liter is it? $(d_{\text{solution}} = 0.9\,\text{g.mL}^{-1};\; O=16,\, C=12,\, H=1:\text{g.mol}^{-1})$
(1) $3.5$ (2) $4.5$ (3) $3$ (4) $4$

214. How many milliliters from a 36.5\% by mass hydrochloric acid solution, with density $1.2\,\text{g.mL}^{-1}$, must be added to 10 liters of water so that the chloride ion concentration becomes approximately $9.5\,\text{ppm}$? $(d_{\text{solution}} = 1\,\text{g.mL}^{-1}$ and $H=1,\, Cl=35.5\,\text{g.mol}^{-1})$
(1) $0.52$ (2) $1.08$ (3) $2.57$ (4) $5.2$

215. Which statement is correct?

• [(1)] There are various ways for the body to supply energy for digestion other than fats and sugars.
• [(2)] Consuming potassium is very useful for preventing bone loss and bone repair.
• [(3)] Converting matter into energy is the only life-giving energy source on Earth.
• [(4)] The per capita consumption of various foods in different countries is the same.

216. Regarding the reaction: $\text{N}_2\text{H}_4(\text{g}) + \text{H}_2(\text{g}) \rightarrow 2\text{NH}_3(\text{g}) + 183\,\text{kJ}$, which statement is correct?

• [(1)] The energy level of the products is lower than that of the reactants.
• [(2)] With the production of each mole of ammonia, $183\,\text{kJ}$ of energy is produced.
• [(3)] The reaction is exothermic and when carried out in a flask, the temperature of it decreases.
• [(4)] When the reaction is carried out at constant temperature, energy must be transferred from the surroundings to the system.

217. Using the data in the table below, for the reaction: $\text{CO}(\text{g}) + 2\text{H}_2(\text{g}) \rightarrow \text{CH}_3\text{OH}(\text{g})$, $\Delta H$ is how many kilojoules?

Bond type	$C\equiv O$	$H-H$	$C-H$	$C-O$	$O-H$
Enthalpy $(\text{kJ.mol}^{-1})$	$1075$	$436$	$414$	$351$	$464$

(1) $-210$ (2) $-180$ (3) $-110$ (4) $-80$

218. White phosphorus spontaneously ignites in air and at room temperature. Therefore, in the laboratory, it is stored under water. What is the role of water in this process?

• [(1)] Catalyst (2) Inhibitor
• [(3)] Decreasing $E_a$ (4) Increasing $E_a$

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219. Considering the figure below, if the bond energies of $\text{N}=\text{O}$, $\text{N}\equiv\text{N}$, and $\text{O}=\text{O}$ are respectively 944, 607, and 496 kJ/mol, what is the sum of $\Delta H$ and $E_a$ (in kJ) per mole for the forward reaction shown?
[Figure: Reaction energy diagram showing 2NO as reactants, a transition state at 381 kJ, and $\text{N}_2 + \text{O}_2$ as products, with $\Delta H(\text{kJ})$ indicated]

• [(1)] $+155$
• [(2)] $+187$
• [(3)] $+441$
• [(4)] $+607$

220. In the reaction (balance the equation): $\text{PI}_3(\text{s}) + \text{H}_2\text{O}(\text{l}) \rightarrow \text{H}_3\text{PO}_4(\text{aq}) + \text{HI}(\text{aq})$, if the initial amount of $\text{PI}_3(\text{s})$ is 20.6 g per liter of water, and after two minutes 4.12 g has been consumed, the average rate of consumption of this substance is approximately how many moles per liter per minute? ($P = 31,\ I = 127\ \text{g·mol}^{-1}$; change in volume is neglected.)

• [(1)] $0.12\ ,\ 3.3\times10^{-4}$
• [(2)] $0.08\ ,\ 3.3\times10^{-4}$
• [(3)] $0.12\ ,\ 6.67\times10^{-4}$
• [(4)] $0.08\ ,\ 6.67\times10^{-4}$

221. In which pair of compounds is the ratio of hydrogen atoms to carbon atoms equal?

• [(1)] Butane, ethyne
• [(2)] Benzene, naphthalene
• [(3)] Ethyne, hydrogen cyanide
• [(4)] Benzene, cyclohexane

222. Which statement is incorrect?

• [(1)] Polymers have molecules with long chains and very high molecular mass.
• [(2)] Polyethylene is a white solid that forms at high pressure by heating ethylene.
• [(3)] In a polyethylene molecule, each carbon atom has four separate covalent bonds with four other atoms (carbon and hydrogen).
• [(4)] In all natural and synthetic polymers, the monomers must have double carbon–carbon bonds.