Question

Match the reactions listed in List 1 with the color of the precipitate(s) listed in List 2.

Answer 1

(a) $C{u}^{2+}+2SC{N}^{-}⟶Cu(SCN{)}_2\downarrow (black)$
$2Cu(SCN{)}_2\downarrow ⟶2CuSCN\downarrow (white)+(SCN{)}_2\uparrow$
(b) $P{b}^{2+}+Cr{O}_4^{2-}⟶PbCr{O}_4\left(yellow\right)$
(c) $\begin{array}{ccccccccc}C{O}_3^{2-}& +& 4H{g}^{2+}& +& 3H_{2}O& ⟶& H{g}_4{O}_{3}C{O}_3\downarrow & +& 6H^{+}\\ & & & & & & Reddishbrown& & \end{array}$
(d) $M{n}^{2+}\left(aq\right)+2O{H}^{-}\left(aq\right)⟶Mn(OH{)}_2\downarrow (white)$
$Mn(OH{)}_2\downarrow +O_2⟶2MnO(OH{)}_2\downarrow \left(brown\right)$

Hence, the correct match is as follows:

A - 4, B - 3, C - 2, D - 1