The process of respiration is:

Consider the reaction:

$\mathrm{KBr}\left(\mathrm{aq}\right)+{\mathrm{AgNO}}_3\left(\mathrm{aq}\right)\to {\mathrm{KNO}}_3\left(\mathrm{aq}\right)+\mathrm{AgBr}\left(\mathrm{s}\right)$

This is an example of:

You are given the following chemical equation:

$\mathrm{Mg}\left(\mathrm{s}\right)+\mathrm{CuO}\left(\mathrm{s}\right)\to \mathrm{MgO}\left(\mathrm{s}\right)+\mathrm{Cu}\left(\mathrm{s}\right)$

This equation represents:

A colourless lead salt, when heated, produces a yellow residue and brown fumes.

(a) Name the lead salt.

(b) Name the brown fumes.

(c) Write a chemical equation of the reaction involved.

When hydrogen burns in oxygen, water is formed and when water is electrolysed, then hydrogen and oxygen are produced. What type of reaction takes place:

(a) in the first case?
(b) in the second case?