2024 JAMB Chemistry Past Questions CBT

The flame used by welders in cutting metals is

Consecutive members of an alkane homologous series differ by

If an element has the electronic configuration 1s²2s²2p⁶3s²3p⁴, it is

Some copper(II) tetraoxosulphate pentahydrate (CuSO₄5H₂O), was heated at 120ºC with the following results:

• Wt of crucible = 10.00 g;
• Wt of crucible + CuSO₄5H₂O = 14.98 g;
• Wt of crucible + residue = 13.54 g.

How many molecules of water of crystallization were lost?

[H = 1, Cu = 63.5, O = 16, S = 32]

The three-dimensional shape of methane is

An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystalline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet taste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a ‘pop’ sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

Compound W is

An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystalline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet taste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a ‘pop’ sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

The molecular formula of X is

An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystalline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet taste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a ‘pop’ sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

Reaction of X with yeast forms the basis of the

A mixture of common salt, ammonium chloride and barium sulphate can best be separated by

Which of the following relationships between the pressure P, the volume V and the temperature T represents an ideal gas behaviour?

What volume of 0.5 M H₂SO₄ will exactly neutralize 20 cm³ of 0.1 M NaOH solution?

In which of the following reactions does hydrogen peroxide act as a reducing agent?

For the reaction:

\( \scriptsize 2Fe^{3+} \: + \: 2I^{-} \: \rightarrow \: 2Fe^{2+}\: + \: I_2 \)

Which of the following statements is true?

The diagram above shows the energy profile for the reaction A + B + = C + D.

From this diagram, it is clear that the reaction is

In dilute solution the heat of the reaction NaOH + HCl → NaCl + H₂O is – 57.3kJ.

Therefore the heat of the reaction:

2NaOH + H₂SO4 → Na₂SO4 + 2H₂O is

For the reactions,

I. Melon oil + NaOH → Soap + Glycerol
II. 3Fe + 4H₂O → Fe₃O4 + 4H₂
III. N₂O4 → 2NO₂

which of the following statement is true?

Which of the following methods may be used to prepare tritoxonitrate(V) acid (nitric acid) in the laboratory?

Lime water which is used in the laboratory detection of carbon(IV) oxide is an aqueous solution of

If an excess of a liquid hydrocarbon is poured into a jar of chlorine, and the sealed jar is then exposed for several hours to bright sunlight, all the chlorine gas is consumed. The hydrocarbon is said to have undergone.

The function of conc. H₂SO₄ in the esterification of ethanoic acid with ethanol is to

A piece of sea shell, when dropped into a dilute solution of hydrochloric acid, produces a colourless, odourless gas which turns clear lime-water milky. The sea shell contains

Which of the following electrodes is used in the electrolysis of bauxite (Al₂O₃) in molten cryolite

An aqueous solution of a metal salt, M, gives a white precipitate with NaOH which dissolves in excess NaOH. The precipitate also dissolves in excess NH₃(aq) to give a colourless solution. M is

The I.U.P.A.C. name for the compound is

Hydrogen is not liberated when trioxonitrate(V) acid reacts with zinc because

The boiling points of water, ethanol, toluene and butan-2-ol are 373.0 K, 351.3 K, 383.6 K and 372.5 K, respectively. Which liquid has the highest vapour pressure at 323.0 K?

In what respect will two dry samples of nitrogen gas differ from each other if sample 1 is prepared by completely removing CO₂ and O₂ from air, and sample 2 is prepared by passing purified nitrogen(I) oxide over heated copper? Sample 1 is

Copper sulphate solution is electrolysed using platinum electrodes. A current of 0.193 amperes is passed for 2 hrs. How many grams of copper are deposited?

\( \scriptsize X \: + \: Y \leftrightharpoons \: Z\) is an equilibrium reaction. The addition of a catalyst

What is the formula of sodium gallate if gallium (Ga) shows an oxidation number of + 3?

If the only pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds, carbon monoxide and high levels of methane, the probable source(s) of the pollution must be

A correct electrochemical series can be obtained from K, Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Hg, Ag, Au by interchanging

A certain industrial process is represented by:

2A_(g) → C_(g) + 3D_(g)  ΔH = +X kJ mol⁻¹

Which of the following conditions will favour the yield of the products?

\( \scriptsize 2MnO^-_{4} \: +\: 10Cl^- \: + \: 16H^+ \: \rightarrow \: 2Mn^{2+} \: + \:  5 Cl_2 \: + \: 8H_2O \)

Which of the following substances serves as an oxidizing agent?

In the reaction H₂O_(g) → H_2(g) + ½O_2(g)

ΔH = -2436000 kJ.

Which of the following has no effect on the equilibrium position?

A stream of air was successively passed through three tubes, X, Y and Z, containing a concentrated aqueous solution of KOH, red hot copper powder and fused calcium chloride, respectively. What was the composition of the gas emanating from tube Z?

In the purification of town water supply, alum is used principally to

Which of the following water samples will have the highest litre value when titrated for the Ca²⁺ ions using soap solution?

Oil spillage in ponds and creeks can be cleaned up by

The solubility of Na₃AsO₄(H₂O)₁₂ is 38.9 g per 100 g H₂O.

What is the mass percentage of Na₃AsO₄ in the solution?

[As = 75, Na = 23, O = 16, H = 1]