NEET Practice Questions (MCQs) with Answers & Solutions

Pure $N_2$ gas is obtained by the reaction of $NH_4Cl$ and $NaNO_2$. The reaction is: $$ NH_4Cl + NaNO_2 ightarrow N_2 + 2H_2O + NaCl $$ This reaction produces nitrogen gas ($N_2$) along with water and sodium chloride.

$NO_2$ gas is released by heating lead nitrate ($Pb(NO_3)_2$). The decomposition reaction is: $$ 2Pb(NO_3)_2 ightarrow 2PbO + 4NO_2 + O_2 $$ This reaction produces nitrogen dioxide ($NO_2$), lead oxide, and oxygen gas.

$N_2O$ (nitrous oxide) is neutral. It does not react with water to form an acidic or basic solution, making it neutral. The other oxides of nitrogen listed (like $N_2O_5$, $N_2O_3$, and $N_2O_4$) are either acidic or have acidic properties.

Among the given compounds, $N_3H$ (hydrazoic acid) is the acidic one. It is a weak acid but more acidic than the other nitrogen hydrides listed. $NH_3$ (ammonia) is basic, $N_2H_4$ (hydrazine) and $N_2H_2$ (diimide) are not acidic.

Laughing gas, or nitrous oxide ($N_2O$), is prepared by heating ammonium nitrate ($NH_4NO_3$). The reaction is: $$ NH_4NO_3 ightarrow N_2O + 2H_2O $$

$P_4O_6$ (tetraphosphorus hexoxide) reacts with water to form phosphorous acid ($H_3PO_3$). The balanced chemical equation is: $$ P_4O_6 + 6 H_2O ightarrow 4 H_3PO_3 $$

$NF_3$ (Nitrogen Trifluoride) is not hydrolyzed because the nitrogen-fluorine bond is very strong due to the high electronegativity of fluorine and the small size of both nitrogen and fluorine atoms, which leads to a high bond dissociation energy. As a result, $NF_3$ is resistant to hydrolysis.

When $BiCl_3$ is added to water, it hydrolyzes to form $BiOCl$ (Bismuth Oxychloride) and HCl. The reaction is: $BiCl_3 + H_2O ightarrow BiOCl + 2HCl$. Therefore, the compound produced is BiOCl.