Question

Urea reacts with water to form $A$ which will decompose to form $B$. $B$ when passed through $Cu^{2+}(aq)$, deep blue colour solution C is formed. What is the formula of C from the following

• A. $CuSO_4$
• B. $[Cu(NH_3)_4]^{2+}$
• C. $Cu(OH)_2$
• D. $CuCO_3.Cu(OH)_2$

Answer 1

Answer: (B)

$[Cu(NH_3)_4]^{2+}$

Answer 2

$NH_{2}CONH_{2}+H_{2}O \to$
$\underset{(A)}{(NH_{4})_{2}CO_{3}} {<=>} \underset{(B)}{2NH_{3}}+H_{2}O+CO_{2}$
$\underset{(B)}{4NH_{3}}+\overset{2+}{Cu(aq)} \to \underset{\text{(deep blue (C)}}{\left[Cu\left(NH_{3}\right)_{4}\right]_{\left(aq\right)}^{2+}}$