NTSE Stage 2 SAT 2014 Question Paper

Above reaction is a neutralization reaction because acid and base react to transform water and salt . Here combination of ${\mathrm{H}}^{+}$ ions and $\mathrm{O}{\mathrm{H}}^{-}$ ions involve.
(b) $2\mathrm{A}\mathrm{g}\mathrm{B}\mathrm{r}\to \mathrm{A}\mathrm{g}+\mathrm{B}{\mathrm{r}}_2$,this reaction is a photochemical reaction which take places in the presence of light.
This reaction is used in photographic process
(c) In reaction $\mathrm{Z}\mathrm{n}\mathrm{C}{\mathrm{O}}_3\to \mathrm{Z}\mathrm{n}\mathrm{O}+\mathrm{C}{\mathrm{O}}_2$,thermal decomposition occurs.
(d) $\underset{\left(\mathrm{s}\right)}{2\mathrm{A}\mathrm{l}}+\underset{\left(\mathrm{s}\right)}{\mathrm{F}{\mathrm{e}}_2{\mathrm{O}}_3}\to \underset{\left(\mathrm{s}\right)}{2\mathrm{F}\mathrm{e}}+\underset{\left(\mathrm{s}\right)}{\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3}$
The reaction of iron oxide and aluminium is an example of thermite reaction, this reaction is used in welding and preparation of metal from their oxides.