Q1. The inner surface of food cans are coated with tin and not with zinc because
(a) zinc is more reactive than tin
(b) zinc has higher melting point than tin
(c) zinc is less reactive than tin
(d) zinc is costlier than tin
Q2. If the pressure over a liquid increases, then its boiling point
(b) does not change
(c) first decreases and then increases
Q3. Which one of the following, alloys contains non-metal as one of its constituents?
Q4. Phosphorus is kept in water to
(a) purify water
(b) make water soft
(c) prevent its contact with oxygen
(d) denature it
Q5. Metallic oxides are ……………. In nature.
Q6. Select from the following a set of three metals which are found in free state.
(a) Copper, gold, iron
(b) Silver, gold, platinum
(c) Aluminium, copper, silver
(d) Gold, iron, silver
Q7. Select from the following the reaction(s) that is/are possible.
I. Al₂(SO₄)₃ (aq) + Cu (s) →
II. FeSO₄ (aq) + Zn (s) →
III. CuSO₄ (aq) + Fe (s) →
IV. Al₂ (SO₄)₃ (aq) + Zn (s) →
(a) I and IV
(b) II and III
(c) I and II
(d) Only I
Q8. When we add aluminium foil to freshly prepared sodium hydroxide solution a gas is produced. Which of the following correctly states the property of this gas?
(a) Colourless and odourless gas which extinguishes a burning matchstick
(b) Colourless and odourless gas which promotes burning of a candle
(c) Brown coloured pungent smelling gas
(d) Colourless and odourless gas which produces a ‘pop’ sound when a burning match stick is brought near it
Q9. When a copper plate is exposed to moist air for long, then it acquires a dull green coating. The green material is
(a) copper sulphate
(b) a mixture of copper hydroxide and copper sulphate
(c) a mixture of copper carbonate and copper sulphate
(d) a mixture of copper carbonate and copper hydroxide
Q10. Which one of the following takes place when water transforms from liquid to gaseous phase?
(a) Distance between the particles change
(b) The colour of the particles change
(c) Size of the particles change
(d) Structure of the particles change