What is the coordination entity formed when excess of aqueous \(KCN\) is added to an aqueous solution of copper sulphate? Why is it that no precipitate of copper sulphide is obtained when \(H_2S(g)\) is passed through this solution?
\(CuSO_{4(aq)}+4KCN_{(aq)}→K_2[Cu(CN)_4]_{(aq)}+K_2SO_4\)
i.e,\([Cu(H_2O)_4]^{2+}+4CN^{-}→[Cu(CN)_4]^{2-}+4H_2O\)
Thus, the coordination entity formed in the process is \(K_2[Cu(CN)_4]\). \(K_2[Cu(CN)_4]\) is a very stable complex, which does not ionize to give \(Cu^{2+}\) ions when added to water. Hence, \(Cu^{2+}\) ions are not precipitated when \(H_2S_{(g)}\)is passed through the solution.
The following questions are for the Visually Impaired Candidates in lieu of Question.
(a) Mention any one mature Harappan site in India.
(b) Mention one Buddhist site in Maharashtra.
(c) Name any one territory which was under the Mughals.
(d) Name the capital of the Vijayanagara Empire.
(e) Name any two centres of the Indian National Movement.
Draw a rough sketch for the curve $y = 2 + |x + 1|$. Using integration, find the area of the region bounded by the curve $y = 2 + |x + 1|$, $x = -4$, $x = 3$, and $y = 0$.
There are three applications of coordination compounds: