Which of the following substances decomposes when an electric current is passed through it?

• A. Glucose solution
• B. Zinc rod
• C. Hydrochloric acid
• D. Tetrachlormethane

Which of the processes represented by the following equations has the greatest positive entropy change?

• A. C₆H₆(l) → C₆H₆ (g)
• B. H₂O(s) → H₂O(I)
• C. CuO(s) + H₂(g) → Cu(s) + H₂
• D. S(s) → S(l)

The mass number of an element is the sum of its

• A. electrons, neutrons and protons
• B. electrons and protons B. electrons and protons B. electrons and protons
• C. protons and neutrons
• D. orbital electrons

How many isomeric dichlorobenzenes are obtainable?

• A) 1
• B) 2
• C) 3
• D) 4

When H₂S is passed into a solution of iron (III) chloride, the solution turns

• A. Pale green
• B. Pale red
• C. Brown
• D. Colourless

(a) State the type of reaction involved in the conversion of:

(i) proteins.to amino acids:

(ii) ethanol to ethene;

(iii) benzene to bromobenzene

(b) Write an equation to show that ethene reasts with hydrogen in the presence of finely divided nickel.

The radioactive emission with the least ionization power is

• A) α−particles
• B) X-rays
• C) γ−rays
• D) β−rays

Alkanols have the general molecular formula

• A) C1H2n-2
• B) C1H2n-1CHO
• C) C1H2n-2OH
• D) C2H2n+1OH

When quicklime dissolves in water?

• A. heat is absorbed
• B. heat is evolved
• C. oxygen is liberated
• D. hydrogen is given off

The most suitable substance for putting out petrol fire is

• A. water
• B. carbon(IV) oxide
• C. fire blanket
• D. sand