a. Which of the following reactions is/ are an endothermic reaction(s) where decomposition also happens?
Respiration
Heating of lead nitrate
Decomposition of organic matter
Electrolysis of acidified water
b. Silver chloride when kept in the open turns grey. Illustrate this with a balanced chemical equation.

Explanation

a Heating of lead nitrate, and electrolysis of acidified water
b
`2AgCl_((s))overset("Sunlight")(to)2Ag_(s)+Cl_(2(g))`
(No deduction for not mentioning state of reactants and products.)