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Multiple choice chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia
The dissolution of ammonia gas in water does not obey Henry's law. On dissolving, a major portion of ammonia molecules reacts with ${H} _{2}O$ to form ${NH} _{4}OH$ molecules. ${NH} _{4}OH$ again dissociates into ${NH} _{4}^{+}$ and ${OH}^{-}$ ions. In solution therefore, we have ${NH} _{3}$ molecules, ${NH} _{4}OH$ molecules and ${NH} _{4}^{+}$ ions and the following equilibrium exist:

${NH} _{3}(g)$ $ \rightleftharpoons{NH} _{3}(l)+{H} _{2}O{(l)}\rightleftharpoons  {NH} _{4}OH{(aq)}\rightleftharpoons  {NH} _{4}^{+}{(aq)}+{OH}^{-}{(aq)}$

Let, ${c} _{1}$ ${(mol/L)}$ of ${NH} _{3}$ pass in liquid state which on dissolution in water forms ${c} _{2}$ ${(mol/L)}$ of ${NH} _{4}OH$. The solution contains ${c} _{3}$ ${(mol/L)}$ of ${NH} _{4}^{+}$ ions.

Concentration of undissociated ammonium hydroxide is________.
  1. ${c} _{1}+{c} _{2}$
  2. ${c} _{2}-{c} _{3}$
  3. ${c} _{1}+{c} _{3}$
  4. ${c} _{1}-{c} _{2}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

${NH} _{3}(g)$$\rightleftharpoons {NH} _{3}(l)+{H} _{2}O\rightleftharpoons  {NH} _{4}OH\rightleftharpoons  {NH} _{4}^{+}+{OH}^{-}$

$c _1$                                                $c _2$                $c _3$
So, remaining moles of undissociated ammonium hydroxide, $NH _4OH=  c _2-c _3$

Multiple choice chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

In the absence of catalyst, ammonia is burnt in an atmosphere of oxygen and produces :

  1. nitogen gas and water

  2. nitric oxide

  3. nitrogen dioxide

  4. nitric acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The combustion of ammonia proceeds to yield nitogen gas and water. With the use of catalyst and under correct conditions of temperature, ammonia reacts with oxygen to produce nitric oxide which is oxidized to nitrogen dioxide and is used in the synthesis of nitric acid.

Multiple choice chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

Sodium dissolved in ammonia has blue colour due to:

  1. solvated sodium molecule

  2. amide ion

  3. solvated electron

  4. lone pair of electrons on nitrogen in ammonia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ammonia solution turns blue when alkali and alkaline earth metals are dissolved in it. The blue color of the solution is considered to be due to ammoniated electrons which absorb energy corresponding to red region of the visible light for the their excitation to higher energy levels. The transmitted light is blue which imparts blue color to the solutions.

Multiple choice chemistry nitrogen and sulfur ammonia-properties and uses ammonia compounds of nitrogen - ammonia

Some of the reasons of reacting $NH _{3}$ with hydrogen chloride are given below. Pick up the correct statement(s) from the following.

  1. The nitrogen atom of $\mathrm{N}\mathrm{H} _{3}$ gains electrons
  2. $\mathrm{N}\mathrm{H} _{3}$ can give a pair of electron
  3. $\mathrm{A}$ proton in $\mathrm{H}\mathrm{Cl}$ can accept an electron pair from $\mathrm{N}\mathrm{H} _3$
  4. The $\mathrm{Cl}^{-}$ formed has a stable configuration of 8 electrons
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

$NH _{3} + HCl \rightarrow NH _{4}Cl$
Ammonia donate its lone pair of electron $HCl$ which will produce $NH _4^+$ and $Cl^-$ ions. Chlorine atom gains one electron and forms chloride ion which has a stable 8 electron configuration in its outermost shell.