A Level Chemistry Practice Questions

Dinitrogen pentoxide is formed by the sequence

In the apparatus shown, $100\ cm^3$ of a mixture of ethane and ethene is passed repeatedly over liquid A, which absorbs only one of the gases. Liquid A is

The standard enthalpy change of combustion of hydrogen is $-286\ kJ\,mol^{-1}$. The thermochemical equation for this change is

In the Born-Haber cycle for aluminium oxide shown, the enthalpy change $\Delta H_6 = -15300.1\ kJ\,mol^{-1}$ is

A current of 2.0 A is passed through aqueous silver nitrate for 180 minutes. The quantity of charge passed is

During the electrolysis of aqueous silver nitrate between inert electrodes, the reaction at the anode is

Passing 21 600 C through aqueous silver nitrate deposits 24.17 g of silver ($A_r = 108$). Taking the electronic charge as $1.6 \times 10^{-19}\ C$, the Avogadro constant, in $mol^{-1}$, is

2.000 g of lead was converted completely into lead(II) chloride, giving 2.682 g of the chloride. Taking $A_r(Cl) = 35.45$, the relative atomic mass of the lead is

A buffer solution is one which

For a gas which behaves ideally, a graph of $pV$ against $p$ at constant temperature is

0.6 mol of $SO_2$ and 2.0 mol of $O_2$ were mixed and allowed to reach equilibrium, $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$. At equilibrium 0.4 mol of $SO_3$ was present. The amounts of $SO_2$ and $O_2$ remaining are

The first ionisation energy of an element is the energy required to remove

Burning butanol raised the temperature of 150 g of water by 10 °C. Taking the specific heat capacity of water as $4.2\ J\,g^{-1}\,K^{-1}$, the heat produced is

For $2H_2 + 2NO \rightarrow 2H_2O + N_2$, doubling $[NO]$ at constant $[H_2]$ raised the rate from 0.024 to $0.096\ mol\,dm^{-3}\,s^{-1}$. The order of reaction with respect to NO is

The reaction is first order with respect to $H_2$ and second order with respect to NO. The rate equation is

When $[H_2] = [NO] = 1\ mol\,dm^{-3}$ the rate is $0.024\ mol\,dm^{-3}\,s^{-1}$ and rate $= k[H_2][NO]^2$. The rate constant is

For $2NO(g) + Cl_2(g) \rightleftharpoons 2NOCl(g)$, raising $[NO]$ from 0.10 to $0.20\ mol\,dm^{-3}$ at constant $[Cl_2]$ raised the initial rate from 0.0001 to $0.0004\ mol\,dm^{-3}\,s^{-1}$. The order with respect to NO is

The iodine liberated in an experiment required $15.0\ cm^3$ of $0.03\ mol\,dm^{-3}$ sodium thiosulphate. The number of moles of thiosulphate used is

The solubility of barium hydroxide at 25 °C is $0.24\ g\,dm^{-3}$. Given that $M_r[Ba(OH)_2] = 171$, the molar concentration of the saturated solution, in $mol\,dm^{-3}$, is

A Bronsted-Lowry acid is a species which

A dynamic equilibrium is a state in which

Fig. 1 shows the first ionisation energies of the elements sodium to argon. The value for aluminium is lower than that for magnesium because the electron removed from aluminium

For the equilibrium $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$, the expression for $K_p$ is

The ideal gas equation is

What is the composition of the free radical of chlorine, $^{35}Cl$?

A mixture of equal volumes of methane and ethane was burned in excess oxygen. After cooling to room temperature, the residual gas absorbed in $KOH_{(aq)}$ was found to be 30 $cm^3$. What was the volume of methane at the beginning?

What is the order of increasing energy of given orbitals in an atom of titanium?

Which statement about relative atomic mass is correct?

Which ion contains an unpaired electron?

What are the products of complete combustion of silane?

What changes in oxidation numbers take place when copper reacts with concentrated nitric acid to give a blue solution and a brown acidic gas?

A research student performed a constant current electrolysis of silver solution using a carbon electrode as the cathode. The electrolysis was allowed to proceed for 0.25 hours at a limiting current of 1.25 A. What is the mass of silver deposited?

Which ion is least polarising?

Which statement always applies to an electrophile?

Element X forms a chloride which is hydrolysed by water to form an acidic solution. Oxide of X reacts with an acid to form a salt. What is X?

Which compound has the greatest numerical value of lattice energy?

With which reagent do phenol and phenylamine give similar reactions?

Which reagent detects the presence of added alcohol in petrol consisting of a mixture of alkanes and alkenes?

Which statement is true about the enthalpy change of atomisation?

The graph shows the mass spectrum of an organic compound X.

An acidic solution of MnO_4^{2-}_{(aq)} undergoes the reaction shown below:

Which statement about transition elements is correct?

Which structure represents the gaseous $SnCl_2$ molecule?

Nitrogen dioxide decomposes on heating according to the equation:

Which two assumptions are made in the kinetic theory of gases?

Which graph shows the variation of volume of an ideal gas with temperature at constant pressure?

Which graph shows the change in electronegativity down a group?

In a reaction $X + Y \rightarrow 2Z$, it was found that doubling the concentration of X caused the rate to increase four times but doubling Y did not affect the rate. What is the rate equation?

Which of the following is the weakest acid in aqueous solution?