Which one of the following is a reduction reaction?

• 2 Mg(s) + O₂(g) → 2 MgO(s)

• S(s) + O₂(g) → SO₂(g)

• 2 HgO(s) $\stackrel{\mathrm{heat}}{\to }$ 2Hg(l) + O₂(g)

• Mg(s) + S(s) → MgS(s)

92.

Which one of the following oxides of nitrogen is known as 'anhydride' of nitric acid?

• N₂O

• N₂O₃

• NO₃

• N₂O₅

Which one of the following is the chemical name for baking soda?

• Sodium bicarbonate (Sodium hydrogen carbonate)

• Sodium carbonate

• Potassium bicarbonate (Potassium hydrogen carbonate)

• Potassium carbonate

Which one of the following is water gas?

• Mixture of carbon monoxide and hydrogen

• Mixture of carbon monoxide and nitrogen

• Mixture of carbon dioxide and water vapour

• Mixture of carbon monoxide and water vapour

Suppose you have four test tubes labelled as 'A', 'B, 'C' and 'D'. 'A' contains plain water, 'B' contains solution of an alkali, 'C' contains solution of an acid, and 'D' contains solution of sodium chloride. Which one of these solutions will turn phenolphthalein solution pink?

• Solution 'A'

• Solution 'B'

• Solution 'C'

• Solution 'D'

Which one ofthe following oxides dissolves in water?

• CuO

• AI₂O₃

• Fe₂O₃

• Na₂O

Which one of the following elements will not react with dilute HCl to produce H₂?

• Hg

• Al

• Mg

• Fe

Which one of the following carbon compounds will not give a sooty flame?

• Benzene

• Hexane

• Naphthalene

• Anthracene

What is the number of mole(s) of H₂(g) required to saturate one, mole benzene?

• 1

• 2

• 3

• 4

Which one of the following statements is correct?

• Covalent bonds are directional

• Ionic bonds are directional

• Both covalent and ionic bonds are directional

• Both covalent and ionic bonds are non-directional