Question

Which one of the following reactions involves oxidation reduction?

• A. $ {{H}_{2}}+B{{r}_{2}}\xrightarrow[{}]{{}}2HBr $
• B. $ NaBr+HCl\xrightarrow[{}]{{}}NaCl+HBr $
• C. $ HBr+AgN{{O}_{3}}\xrightarrow[{}]{{}}AgBr+HN{{O}_{3}} $
• D. $ 2NaOH+{{H}_{2}}S{{O}_{4}}\xrightarrow[{}]{{}}N{{a}_{2}}S{{O}_{4}}+2{{H}_{2}}O $

Answer 1

Answer: (A)

(b) $NaBr + HCl \longrightarrow NaCl + HBr$
It is a substitution reaction.
(c) $HBr + AgNO _{3} \longrightarrow AgBr + HNO _{3}$
It is a substitution and precipitation reaction because $AgBr$ is precipitated during this reaction.
(d) $2 NaOH + H _{2} SO _{4} \longrightarrow Na _{2} SO _{4}+2 H _{2} O$ It is a neutralisation reaction because acid and base are reacting to produce salt and $H _{2} O .$
(a) $\overset{0}{ H }_{2}+\overset{0}{B}r _{2} \longrightarrow 2 H ^{+} Br ^{-}$
This is oxidation reduction reaction because during this reaction oxidation number are changing.