Chemistry
Give reasons:
(a) When ammonia gas is passed over black copper oxide in a combustion tube a reddish-brown substance is left behind.
(b) Quick lime is not used to dry hydrogen chloride gas.
Answer
(a) When ammonia gas is passed over black copper oxide in a combustion tube a reddish-brown substance is left behind because ammonia gas reduces black copper [II] oxide to brown Copper.
2NH3 + 3CuO ⟶ 3Cu + 3H2O + N2 ↑
(b) Quick lime is not used to dry hydrogen chloride gas because quick lime reacts with hydrogen chloride gas
Related Questions
(a) Give the IUPAC name of the following organic compounds:
(b) Draw the structural diagram for the following compounds:
- but-2-yne
- 1, 1, 1, trichloro methane
- pentan-2-ol
Give one significant observation when:
(a) Excess of chlorine gas reacts with ammonia.
(b) Zinc nitrate is strongly heated in a test tube.
The electron affinity of an element X is greater than that of element Y.
(a) How is the oxidising power of X likely to compare with that of Y?
(b) How is the electronegativity of X likely to compare with that of Y?
(c) State whether X is likely to be placed to the left or to the right of Y in the periodic table?
Write balanced chemical equations for the following reactions:
(a) Ammonium chloride reacts with calcium hydroxide.
(b) Nitric acid reacts with zinc carbonate.
(c) Concentrated sulphuric acid is added to hydrated copper sulphate.