Question: \[{{\text{H}}_2}{\text{S}}\] reacts with lead acetate to form a black compound which reacts with \[{...

Question

${{\text{H}}_2}{\text{S}}$ reacts with lead acetate to form a black compound which reacts with ${{\text{H}}_2}{{\text{O}}_2}$ to form another compound. The colour of this another compound is:
A.Pink
B.Black
C.Yellow
D.White

Answer 1

Solution

The displacement reaction will occur when we react hydrogen sulphide gas with lead acetate. The sulphate of lead will form after further reaction with hydrogen peroxide.

Complete answer:
The reaction of hydrogen sulphide that is ${{\text{H}}_2}{\text{S}}$ with lead acetate that is ${\left( {{\text{C}}{{\text{H}}_3}{\text{COO}}} \right)_2}{\text{Pb}}$ will result in the formation of lead sulphide which is black in colour along with acetic acid. The reaction occurs as:
${{\text{H}}_2}{\text{S}} + {\left( {{\text{C}}{{\text{H}}_3}{\text{COO}}} \right)_2}{\text{Pb}} \to {\text{PbS}} + 2{\text{C}}{{\text{H}}_3}{\text{COOH}}$
The lead sulphide reacts with hydrogen peroxide that is ${{\text{H}}_2}{{\text{O}}_2}$ to form lead sulphate which is white in colour. The reaction occurs as:
${{\text{H}}_2}{{\text{O}}_2} + {\text{PbS}} \to {\text{PbS}}{{\text{O}}_4} + {{\text{H}}_2}{\text{O}}$

Hence the correct option is D that is white.

Additional information:
Hydrogen sulphide is a foul smelling gas. It has a smell of rotten eggs and is very poisonous gas. It is mainly produced by the decomposition of organic matter anaerobically that is in the absence of oxygen. It also occurs in volcanic eruptions. Hydrogen sulphide is used in the extra element detection of the presence of lead in the given organic compound. It is also used in Analytical chemistry. In hydrogen peroxide the oxidation state of oxygen is minus 1. It has an open book like structure. The two oxygens are bonded by peroxide linkage.

Note:
Lead sulphate is used in the formation of electrochemical cells. They are used to make electrodes which are used in the batteries of automobiles. It is not or partially soluble in water. It is however toxic in nature and can cause irritation in skin and can cause eye burns. Long exposure to lead sulphate may lead to anaemia, kidney damage, and problems in the central nervous system.