2020 JAMB Chemistry Past Questions CBT

Which of the following substances is not a homogenous mixture?

Calculate the number of moles of (H⁺) present in 1 dm³ of 0.5 M solution of H₂SO₄.

Given that the mass of gas occupies 1 dm³ at 300 K, at what temperature will its volume be doubled, keeping the pressure constant?

For iodine crystals to sublime on heating, the particles must acquire energy that is

An element, E with the electronic configuration of 1s² 2s² 2p⁶3s² 3p³, the reaction of E with a halogen Y can give

While the difference in electronegativity between bonded atoms increases, the polarity of the bond

Elements P, Q and R belong to groups I, V and VII, respectively. Which of the following is TRUE about the bond types of PQ and QR?

The diagram above would be used in determining the amount of

The major effect of air pollution in coastal waters is the

Determine the pH of a 2.50 × 10^-5 M solution of potassium hydroxide.

In the electroplating of a metal M with silver in the process, the metal M is the

The only process that leads to an increase in entropy from the following is

\(\scriptsize2CO_{\left ( g \right )} + O_{2\left ( g \right )}\rightarrow 2CO_{2\left ( g \right )}\)

In the above reaction, the standard heats of reaction of CO_(g) and CO_2(g) are – 297 KJ mol^-1 and – 396 KJ mol^-1, respectively. The heat change of the reaction is

The rate law obtained for a given reaction is expressed as r = K [X]ⁿ [Y]^m. The overall order of the reaction becomes

The gas liberated from the oxidation of concentrated hydrochloric acid with manganese(IV) oxide is used in the

2Cl_2(g) + 2H₂O_(g)  → 4HCl_(g) + O_2(g)

∆H⁰ = +15 KJ mol^-1

In the above equilibrium reaction, an increase in temperature will

A filter paper soaked in lead ethanoate solution will turn black in the presence of

Which of the following is an aromatic compound?

One of the methods used to convert hard water to soft water is

The quantity of electricity that will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution is

(F = 96500 C mol^-1)

Which of these hydrocarbons burns in air with a sooty flame?

A mixture containing iodine and sulphur crystals can be separated with

A compound composed of Al, Si, O and H is

If the partial pressure of oxygen in a sample of air is 452 mmHg and total pressure is 780 mmHg. What is the mole fraction of oxygen?

The vapour density of XO₂  has a vapour density of 32. What is the atomic mass of X?

Four elements A, B, C and D have atomic numbers 2, 6, 16 and 20, respectively. Which of these elements is a metal?

CH₃COOH is

Which of these salts will give a precipitate when treated with NaOH solution?

The process whereby a salt loses its water of crystallization to the atmosphere on exposure is called

Which of the following elements can catenate?

The only metal from the following that liberates hydrogen from cold water in bubbles is

What is the ratio of carbon : hydrogen : oxygen found in a carbohydrate?

When sugar is dissolved in tea, the reaction is always accomplished by

What is the oxidation state of chlorine in HClO₄?

Which of the allotropes of carbon is used in the decolourization of sugar?

Vulcanization deals with the removal of

The solubility curve illustrates the variation of solute concentration with

Ammonia gas reacts with which of the following to form a dense white fume?

Which of the following alloys contains iron?

Which of these is an unsaturated hydrocarbon?