Question

The correct order of increasing $\left[ H _{3} O ^{+}\right]$ in the following aqueous solutions is

• A. $0.01 \,M\, H _{2} S <0.01 \,M\, H _{2} SO _{4}<0.01 \,M \,NaCl$ $<0.01 \,M \,NaNO _{2}$
• B. $0.01 \,M\, NaCl <0.01 \,M\, NaNO _{2}<0.01 \,M\, H _{2} S$ $<0.01 \, M H _{2} \,SO _{4}$
• C. $0.01 \,M\, NaNO _{2} < 0.01 \,M\, NaCl < 0.01 \,MH _{2} S$ $<0.01 \,M\, H _{2} SO _{4}$
• D. $0.01 \,MH _{2} S < 0.01 \,M\, NaNO _{2} < 0.01 \,M\,NaCl$ $ < 0.01 \,M\,H _{2} SO _{4}$

Answer 1

Answer: (C)

$H _{2} SO _{4}$ is strong acid having $pH < 7 .\, NaNO _{2}$ on hydrolysis gives alkaline solution of $pH >7 \,NaCl$ is neutral and $H _{2} S$ is weak acid.