When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will?

A. decrease, since only a fraction of the water molecules has changed to vapour

B. remain constant, because the total number of water molecules has not changed

C. increase, because the water molecules can now reach every part of the sealed tube

D. decrease, since water boils under reduced pressure

E. increase, because the water vapour molecules now strike the walls of the tube more frequently because of their increased velocity

An element X has two isotopes, ²⁰₁₀X and ²⁰₁₀X,
present in the ratio 1:3. The relative atomic mass of X would be?

A. 20.5

B. 21.0

C. 21.5

D. 22.0

E. 22.5

Which of the following is a neutralization reaction? Addition of

A. nitric acid to hydrochloric acid

B. nitric acid to sulphuric acid

C. nitric acid to distilled water

D. nitric acid to sodium hydroxide

E. sodium chloride to distilled water

A current of 10.0A was passed for 1 hour through a solution of copper (ll) sulphate between the copper electrodes. Which of the following observation would be correct?
(1 Faraday = 96,500 coulobms) (i) 0.186 mole of copper is dissolved from the anode. (ii) 0.372 mole of copper is deposited on the cathode. (iii) the original Cu²⁺ ion concentration of the solution remains unchanged. (iv) the original Cu²⁺ ion concentration of the solution dec

A. i and ii

B. i and iii

C. i and iv

D. ii and iii

E. ii and iv

In the preparation of carbon monoxide by heating ethanedioic acid with concentrated sulphuric acid, the concentrated sulphuric acid act as?

A. an oxidizing agent

B. a reducing agent

C. a dehydrating agent

D. a reaction medium

E. a catalyst

When copper powder is heated with concentrated sulphuric acid, the gas produced is?

A. hydrogen sulphide

B. sulphur dioxide

C. sulphur trioxide

D. hydrogen pentasulphide

E. sulphur pentoxide

Magnesium ribbon was added to each of the following aqueous solution in turn: H₂SO₄, AgNO₃, HNO₃, HCl, NH₃, HCl, NH₃. In which case does the magnesium become covered with a dark precipitate?

A. H₂SO₄

B. AgNO₃

C. HNO₃

D. NH₃

E. HCl

How many grams of methylacetylene (propyne) CH₃ — C Ξ CH will completely discharge the colour of 8g of bromine?
(Br = 80, C = 12, H = 1)

A. 0.5

B. 1.0

C. 2.0

D. 3.0

E. 4.0

What weight of sodium hydroxide is required to make 500 cm³ of 0.2 M solution?

(Na = 23, O = 16, H = 1)

A. 40 g

B. 20 g

C. 10 g

D. 4 g

E. 2 g

Which of the following combinations of conditions may increase the rate of a chemical reaction?

A. Decrease in temperature, increase in concentration of the reactants

B. Increase in temperature, addition of a catalyst, decrease in the surface area of the reactants

C. Increase in temperature, increase in concentration, addition of a catalyst and increase in the surface area of the reactants

D. Decrease in temperature concentration and surface area of the reactants

E. Additionof a catalyst and in the absence of light