2015 JAMB Chemistry Past Questions*

Pollution of water by crude oil can lead to

When a few drops of barium chloride is added to an unknown sample acidicified with hydrochloric acid, a white precipitate insoluble in excess of acid was obtained. The likely anion in the sample is

Oxygen in air can be removed using

Calculate the pH of a solution of 0.0001 mol/dm³ hydrochloric acid.

Which of the following drying agents is not suitable for drying hydrogen sulphide?

Diamond is used in making jewellery due to its

The presence of impurities will make the melting point

The discovery that protons an neutrons are concentrated at the nucleus of an atom was postulated by

Which of the following is a hygroscopic substance?

In a chemical reaction, when the energy of the colliding reaction particles is less than the activation energy, the reaction will

The monomer of natural rubber is

The oxidation number of Boron in NaBH₄ is

PCl_5(l) \(\rightleftharpoons \) PCl_3(l)  + Cl_2(g)  ∆H = +ve

In the reaction above, the forward reaction is favoured by

Which of the following halogens is the most reactive?

A gas that forms a black precipitate with lead (II) ethanoate is

The common ore of iron is

A property common to the above structures is that they have the same

The type of salt that ionizes to produce three different types of ions in solution is

H₂S_(g) +  Br_2(g) \(\rightarrow \) 2HBr_(g)  +  S_(s)

In the above reaction, the oxidation agent is

The process whereby a gaseous body losses some of its kinetic energy to a colder body is referred to as

Which of the quantum numbers determine the energy sub-level in an orbital?

Fehling’s solution can be used to distinguish between

What is the molecular formular for a compound with empirical formula CH₂ and vapour density 42?

The separation technique that is based on the principle of solubility of solid two miscible liquids is

Hydrogen bond can be found in

24 g of magnesium reacts with dilute hydrochloric acid. Calculate the volume of hydrogen gas evolved at s.t.p. [Mg = 24, molar volume of gas at s.t.p = 22.4 dm³]

Aluminium is used as electrical cable due to its

A chemical reaction with enthropy change of 20 JK^-1 and free energy change +55000 J occurred at -23⁰C. Calculate the enthalpy change.

The enzyme invertase converts sucrose into

The number of lone pair of electrons in water molecules is

In the illustration below, x and y respectively represent ______

n monosaccharide \(\normalsize \overset{x}{\underset{y}{\rightleftharpoons} }\) polysaccharide – n water.

The main product of the reaction between phosphorus (V) chloride and ethanol is

The bond-breaking energies in an endothermic reaction is usually

In the reaction below, X and Y respectively are:

\(\scriptsize\;^{234}_{90}Th \rightarrow\; ^{X}_{y}Pa\;+\;\beta \)

The compound of calcium used to make refractory furnace lining is

The mass of copper deposited when a current of 2.0 A is passed through a solution of copper salt for 60 minutes [Cu = 64, F = 96500 C mol^-1]

Which of the following compounds will liberate carbon (IV) oxide on reaction with sodium tetraoxocarbonate (IV)?

Kerosene is a petroleum fraction that distils over in temperature range of

The preference in the usage of asbestos support to platinum block as a catalyst can be attributed to its

In the reduction of ethyl ethanoate with LiAlH₄, the product obtained is

A sample of salt was heated on a Bunsen flame. If the colour of the flame turned bluish-green, the metal present is likely to be.

A salt that loses moisture on exposure to the atmosphere is said to be

In the graph above, at what temperature is the solubility of KHCO₃ and NaCl the same?

1050cm³ of helium gas was produced a – 33ºC and 700 mmHg. What volume would the gas occupy at 23ºC and 750 mmHg?

In the reaction below X is a

\(\scriptsize\;^{14}_{7}N+X\;\rightarrow \;^{17}_{8}O\;+\;^{1}_{1}H\)

The colour of phenolphithalein in an alkaline medium is

Calculate the molecular formular of a compound whose empirical formula is CH₂O and relative molecular mass is 120. [C = 12, O = 6, H = 1].

MnO_2(s) + 4HCl_(aq)  \(\rightarrow\)MnCl_2(aq) + Cl_2(g)  + 2H₂O_(l)

In the reaction above, MnO₂ acts as

Calculate the mass of magnesium that would be deposited by 8 Faraday of electricity. [Mg = 24].

Which of the following hydrocarbons will not undergo polymerization?