2025 JAMB Chemistry Past Questions CBT

A pure solid usually melts

At the same temperature and pressure, 50 cm³ of nitrogen gas contains the same number of molecules as:

8 g of CH₄ occupies 11.2 dm³ at s.t.p. What volume would 22 g of C₃H₈ occupy under the same conditions?

To what temperature must a gas at 273 K be heated in order to double both its volume and pressure?

For a gas the relative molecular mass is equal to 2Y. What is Y?

The densities of two gases X and Y are 0.5 g dm⁻³ and 2.0 g dm⁻³, respectively. What is the rate of diffusion of X relative to Y?

An increase in temperature causes an increase in the pressure of a gas because:

The shape of ammonia molecule is:

The number of electrons in the valence shell of an element of atomic number 14 is:

Which of the following physical properties decreases down a group in the periodic table?

A major effect of oil pollution in coastal waters is the:

Sodium chloride has no solubility product value because of its:

The solubility in mol dm⁻³ of 20.2 g of potassium trioxonitrate(V) dissolved in 100 cm³ of water at room temperature is:

[K = 39, O = 16, N = 14]

A few drops of concentrated HCl are added to about 10cm³ of a solution of pH 3.4. The pH of the resulting mixture is:

Which of the following compounds is a base?

20 cm³ of a 2.0M solution of ethanoic acid was added to excess 0.05M sodium hydroxide. The mass of the salt produced is: [Na = 23, C = 12, O = 16, H = 1]

What volume of oxygen measured at s.t.p. would be liberated on electrolysis by 9650 coulombs of electricity?

Crude copper could be purified by electrolysis of concentrated copper(II) chloride if the crude copper is:

\( \scriptsize H^-_{(aq)} + H_2O_{(l)} \rightarrow H_{2(g)} + OH^-_{(aq)}\)

From the equation, it can be inferred that the:

Which of the metals CANNOT replace hydrogen from alkaline solution?

Clothes should be properly rinsed with water after bleaching because:

Which of these solutions will give a white precipitate with a solution of barium chloride acidified with hydrochloric acid?

SO₃ is NOT directly dissolved in water in the preparation of H₂SO₄ by the contact process because:

In an electrolytic set-up to protect iron from corrosion, the iron is:

Which of the following orbitals of carbon are mixed with hydrogen in methane?

Which reagent will confirm the presence of unsaturation in a compound?

The stability of ionic compounds is generally due to the:

Which of the following statements is FALSE about isotopes of the same element?

Helium is often used in observation balloons because it is:

When plastics and packaging materials made from chloroethene are burnt in the open, the gases released are most likely to contain:

Deliquescent substances are also:

The difference between colloids and suspensions is brought out clearly by the fact that while colloids:

In general, an increase in temperature increases the solubility of a solute in water because:

Neutralization involves a reaction between H₃O⁺ and:

Which of the following solutions will have a pH < 7?

What is the pH of a 2.50 × 10⁻⁵ M hydroxide solution?

Sulphur exists in several forms in the solid state. This property is known as:

A gas that will turn orange potassium heptaoxodichromate (VI) solution to clear green is:

Which ion will give a white precipitate with aqueous NaOH and the precipitate is soluble in excess of the base?

In the extraction of iron in the blast furnace, limestone is used to: