Question

$Pb{\left( {C{H_3}COO} \right)_2}$ gives ____ colour with ${H_2}S$ .
(A) Black
(B) White
(C) Red
(D) Orange

Answer 1

Hint: With the formula $Pb{\left( {C{H_3}COO} \right)_2}$, lead acetate is an ionic molecule that contains lead in the +2 oxidation state. It is a crystalline white substance and tastes a little bit sweet. When it reacts with ${H_2}S$ it gives $PbS$ as one of the products and is black in colour.

Complete Step by Step Solution:
Before finding the colour of the product obtained after reacting $Pb{\left( {C{H_3}COO} \right)_2}$ with ${H_2}S$ let us first know what lead acetate is and what its properties are.
 $C{H_3}CO{O^ - }$ anion and $P{b^{2 + }}$ cation are present in lead(II) acetate. It is a substance that is water soluble. Due to its sweet flavour, it is frequently encountered as trihydrate lead acetate, sometimes known as sugar of lead. $Pb{\left( {C{H_3}COO} \right)_2}.3{H_2}O$ is the molecular formula for trihydrate lead acetate. It is a monoclinic crystalline material that is white in colour and soluble in water. It's used in paints, gold cyanidation plants, dyeing, and other things.

With the formula $Pb{\left( {C{H_3}COO} \right)_2}$ , lead acetate is an ionic molecule that contains lead in the +2 oxidation state. It is also known as lead diacetate, sugar of lead, lead salt, Plumbous acetate, and Goulard's powder. Lead(II) ethanoate is the formal name given to it by IUPAC. Similar to other lead compounds, lead acetate is poisonous. However, it still has a number of uses, including as a fixative and a reagent in the synthesis of other chemicals. It was also employed as a sweetener, but due to its toxicity, it was quickly outlawed.
It is black in colour and produces $PbS$ as one of the byproducts when it reacts with ${H_2}S$ .

The chemical equation involved here is:
 $Pb{\left( {C{H_3}COO} \right)_2} + {H_2}S\,\, \to \,\,2C{H_3}COOH + PbS$
Here $PbS$ is black in colour.
Hence, option A. is the answer.

Note: Different chemical and physical properties should be known to come to a conclusion. For such questions one must know how different chemicals behave when reacted with acids or bases or some other chemical compounds. Also we should know the chemical names of the compounds as the questions may not give a chemical formula but ask to write the reaction equation.