GCE Advanced Level — Chemistry Quiz

Q1
Which of the following compounds can undergo a self-condensation reaction when treated with dilute aqueous $\ce{NaOH}$ ?
Methanal
Trichloroethanal
2,2-Dimethylpropanal
Propanone
Benzaldehyde
Q2
A mass of $0.0142\text{ g}$ of $\ce{Na2SO4}$ is dissolved in $250.0\text{ cm}^3$ of distilled water. The $\ce{Na+}$ concentration in $\text{mol dm}^{-3}$ and ppm ( $\text{mg kg}^{-1}$ ) are respectively,

(Relative atomic mass: $\text{Na} = 23$ , $\text{S} = 32$ , $\text{O} = 16$ ; density of solution = $1.00\text{ kg dm}^{-3}$ )
$4.0 \times 10^{-4}$ and $9.2$
$4.0 \times 10^{-4}$ and $18.4$
$8.0 \times 10^{-4}$ and $9.2$
$8.0 \times 10^{-4}$ and $18.4$
$1.6 \times 10^{-3}$ and $36.8$
Q3
A 4.0 L flask contains $\ce{N2}$ gas at 2.0 atm and a separate 4.0 L flask contains $\ce{O2}$ gas at 3.0 atm, both at the same temperature. The gases are mixed by opening a stopcock connecting the flasks, and the final volume is 8.0 L. What is the mole fraction of $\ce{N2}$ in the mixture?
0.31
0.50
0.69
0.40
0.60
Q4
The reversible reaction $\ce{N2O4(g) <=> 2NO2(g)}$ is at equilibrium in a closed rigid container at a constant temperature. If a small amount of $\ce{NO2(g)}$ is added to the container, how do the rates of the forward and reverse reactions change immediately after the addition?
Both forward and reverse reaction rates increase.
Both forward and reverse reaction rates decrease.
The forward reaction rate increases, while the reverse reaction rate remains unchanged.
The reverse reaction rate increases, while the forward reaction rate remains unchanged.
The reverse reaction rate increases, while the forward reaction rate decreases.
Q5
A $50.0\text{ cm}^3$ volume of $0.10\text{ mol dm}^{-3}$ $\ce{NH3(aq)}$ is titrated with $0.10\text{ mol dm}^{-3}$ $\ce{HCl(aq)}$ at 298 K. What is the pH of the resulting solution exactly at the equivalence point? (For $\ce{NH3}$ , $K_b = 1.0 \times 10^{-5}\text{ mol dm}^{-3}$ at 298 K. Assume $K_w = 1.0 \times 10^{-14}\text{ mol}^2\text{ dm}^{-6}$ and $\log 5 = 0.70$ )
4.15
5.15
5.85
8.85
9.15
Q6
What is the IUPAC name of the compound $\ce{CH3CH2COOH}$ ?
Propanoic acid
Propionic acid
Propan-1-oic acid
Propanal
Propan-1-ol
Q7
The concentration of a dilute aqueous solution of a weak monoacidic base $\ce{BOH}$ is $C\text{ mol dm}^{-3}$ and its base dissociation constant is $K_b$ at 298 K. Assuming the ionic product of water is $K_w$ , which of the following expressions gives the pH of the solution at 298 K?
$\text{pH} = \text{p}K_w - \frac{1}{2}\text{p}K_b - \frac{1}{2}\log C$
$\text{pH} = \text{p}K_w - \frac{1}{2}\text{p}K_b + \frac{1}{2}\log C$
$\text{pH} = \text{p}K_w + \frac{1}{2}\text{p}K_b + \frac{1}{2}\log C$
$\text{pH} = \frac{1}{2}\text{p}K_w - \frac{1}{2}\text{p}K_b + \frac{1}{2}\log C$
$\text{pH} = \text{p}K_w + \frac{1}{2}\text{p}K_b - \frac{1}{2}\log C$
Q8
Which expression gives the correct volume ( $\text{cm}^3$ ) of $70.0\%$ ( $w/w\%$ ) concentrated $\ce{HClO4}$ acid with density $1.67\text{ g cm}^{-3}$ required to prepare $250\text{ cm}^3$ of a $0.100\text{ mol dm}^{-3}$ solution of $\ce{HClO4}$ ? (Relative atomic mass: $\text{H} = 1$ , $\text{O} = 16$ , $\text{Cl} = 35.5$ )
$\frac{100}{1.67} \times \frac{70.0}{100.5} \times \frac{0.100}{1000} \times 250$
$\frac{100}{1.67} \times \frac{100.5}{70.0} \times \frac{0.100}{1000} \times 250$
$\frac{1.67}{100} \times \frac{100.5}{70.0} \times \frac{1000}{0.100} \times 250$
$\frac{100}{1.67} \times \frac{100.5}{70.0} \times \frac{1000}{0.100} \times \frac{1}{250}$
$\frac{1.67}{100} \times \frac{70.0}{100.5} \times \frac{0.100}{1000} \times 250$
Q9
Which of the following pairs of species have the same ground state electronic configuration?
$\ce{Cr^3+}$ and $\ce{Fe^3+}$
$\ce{Mn^2+}$ and $\ce{Fe^3+}$
$\ce{Co^2+}$ and $\ce{Ni^2+}$
$\ce{Cu^2+}$ and $\ce{Zn^2+}$
$\ce{Sc^3+}$ and $\ce{Ti^3+}$
Q10
The reaction $\ce{2NO(g) + Cl2(g) -> 2NOCl(g)}$ occurs via the following mechanism. Step 1: $\ce{NO(g) + Cl2(g) <=> NOCl2(g)}$ (fast equilibrium, equilibrium constant $K$ ) Step 2: $\ce{NOCl2(g) + NO(g) -> 2NOCl(g)}$ (slow, rate constant $k_2$ ) What is the overall rate law for this reaction?
$\text{Rate} = k_2[\ce{NO(g)}][\ce{Cl2(g)}]$
$\text{Rate} = k_2 K[\ce{NO(g)}]^2$
$\text{Rate} = k_2 K[\ce{NO(g)}]^2[\ce{Cl2(g)}]$
$\text{Rate} = k_2 K[\ce{NO(g)}][\ce{Cl2(g)}]^2$
$\text{Rate} = k_2[\ce{NOCl2(g)}][\ce{NO(g)}]$