Question

The reaction of zinc with dilute and concentrated nitric acid, respectively, produces :

• A. $N_2O$ and $NO_2$
• B. $N_2O$ and NO
• C. NO and $N_2O$
• D. $NO_2$ and $N_2O$

Answer 1

Answer: (A)

$N_2O$ and $NO_2$

Answer 2

$Zn$ reacts with dil. $HNO _{3}(20 \%)$ to form nitrous oxide $\left( N _{2} O \right)$
$Zn$ reacts with conc. $HNO _{3}(70 \%)$ to form nitrogen dioxide $\left( NO _{2}\right)$
$4 Zn +10 HNO _{3}{\text{( dil.)}} \longrightarrow 4 Zn \left( NO _{3}\right)_{2} N _{2} O +5 H _{2} O$
$Zn +4 HNO _{3}{\text{( conc )}} \longrightarrow Zn \left( NO _{3}\right)_{2}+2 NO _{2}+2 H _{2} O$