Chemistry
Abhishek was given a salt 'X' which was white in colour for analysis. On strong heating it produced a yellow residue, a colourless gas and also a reddish-brown gas. The solution of the salt ‘X’ when tested with excess of ammonium hydroxide produced a chalky white insoluble precipitate.
(a) Name the coloured gas evolved when Abhishek heated the salt strongly.
(b) Which cation was present in the sample given to Abhishek?
(c) Identify the salt given to Abhishek for analysis.
Answer
(a) Nitrogen dioxide
Reason — The reddish-brown colour indicates that the gas is Nitrogen dioxide.
(b) Pb2+ (Lead)
Reason — The chalky white insoluble precipitate with excess of ammonium hydroxide indicates that the cation present is Pb2+.
(c) Lead nitrate [Pb(NO3)2].
Reason — The given salt is a nitrate salt as nitrogen dioxide (NO₂), is a common product obtained from heating nitrates. As the cation is lead, hence the salt is Lead nitrate.
Related Questions
(a) Ranjana wants to prove that ammonia is a reducing agent. To demonstrate this, she passes ammonia gas over heated copper oxide. What will she observe?
(b) Write a balanced chemical equation for the above reaction.
Name the alloy which is made up of:
(a) Copper, Zinc and Tin
(b) Lead and Tin
Given below in column A is a schematic diagram of the electrolytic reduction of alumina. Identify the parts labelled as A, B and C with the correct options from the Column B.
Element 'X' forms an oxide with the formula X2O3 which is a solid with high melting point. 'X' would most likely be placed in the group of the Periodic Table as:
(a) Na
(b) Mg
(c) Al
(d) SiJustify your answer in the above question (1).