Match each of the following terms with its appropriate description.

a$.$ redox reaction

e$.$ oxidizing agent

b$.$ oxidation

f$.$ reduction

c$.$ oxidation number

d$.$ reducing agent

g$.$ galvanic cell

$21.$ an electron acceptor

$22.$ a device which converts chemical energy into electrical energy

$23.$ expresses electron loss or gain by an atom

$24.$ involves exchange of electrons

$25.$ an eiectron donor

$26.$ a process in which an atom or ion gains an electron$($s$)$

$27.$ a process in which an atom or ion loses an electron$($s$)$

Problem $($Thinking$)$

Balance the following redox reaction using half reaction method in basic conditions. $[5$ Marks$]$

$A{g}_{(s)}+C{r}_2{O}_7^{2-}{?}_{(aq)}A{g}_{(aq)}^{+}+C{r}_{(aq)}^{3+}$

Balance the following redox reaction using the half reaction method in acidic conditions. $[5$ Marks$]$

$Mn{O}_{2(s)}+A{l}_{(s)}M{n}_{(s)}+A{l}_2{O}_{3(s)}$

$4$