Which of the following will occupy the volume 2.8 litres at S.T.P.?
(Atomic weight: C = 12, O = 16, Cl = 35.5, S = 32)

1. 2 moles of carbon dioxide
2. 7.1 g of chlorine
3. 8 g of sulphur dioxide
4. 56 g of carbon monoxide

A salt solution which gives a reddish-brown precipitate with NaOH and a white precipitate with BaCl₂ solution is:

1. CuSO₄
2. Ca(NO₃)₂
3. Fe₂(SO₄)₃
4. FeCl₃

The gas evolved in the diagrammatic set up given below turns calcium hydroxide solution milky. The gas evolved is:

1. CH₄
2. C₂H₆
3. CO₂
4. SO₂

Which gas is evolved when ammonia gas is passed over buff yellow PbO?

1. N₂O
2. NO
3. N₂
4. NO₂