When a copper strip is placed in a solution of silver nitrate, copper nitrate and silver are formed. Name the reaction.

Consider the general reaction:

${\mathrm{A}}^{2+} + {\mathrm{B}}^{2-} \to \mathrm{A} + \mathrm{B}$

Name the reducing agent.

Identify the type of reaction in the following example:

${\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right) +{\mathrm{BaCl}}_2\left(\mathrm{aq}\right) \to {\mathrm{BaSO}}_4\left(\mathrm{s}\right) +2\mathrm{NaCl}\left(\mathrm{aq}\right)$

Identify the type of reaction in the following example:

$2{\mathrm{H}}_2\left(\mathrm{g}\right) +{\mathrm{O}}_2\left(\mathrm{g}\right) \to 2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$