Chemistry > p Block Elements > 11.0 Oxyacids of Nitrogen
p Block Elements
1.0 Group $13$ – The Boron Family
2.0 Boron
3.0 Compounds of boron
4.0 Compounds of Aluminium
5.0 Group $14$ – The Carbon family
6.0 Allotropes of Carbon
7.0 Compounds of Carbon
8.0 Properties of Silicon
9.0 Group $15$-The Nitrogen Family
10.0 Oxides of nitrogen
10.1 Nitrogen Oxide $N_2O$ or Laughing gas (Neutral)
10.2 Nitric Oxide $NO$ (Neutral)
10.3 Nitrogen trioxide $N_2O_3$
10.4 Nitrogen dioxide or Di-nitrogen tetroxide $NO_2$ or $N_2O$
10.5 Nitrogen pentaoxide $N_2O_5$
11.0 Oxyacids of Nitrogen
11.1 Nitric acid $HNO_3$
11.2 Oxidation of Metalloid and Inorganic compounds by Nitric acid
11.3 Action of Metals & Proteins
12.0 Phosphorus
13.0 Oxygen
14.0 Sulphur
11.1 Nitric acid $HNO_3$
10.2 Nitric Oxide $NO$ (Neutral)
10.3 Nitrogen trioxide $N_2O_3$
10.4 Nitrogen dioxide or Di-nitrogen tetroxide $NO_2$ or $N_2O$
10.5 Nitrogen pentaoxide $N_2O_5$
11.2 Oxidation of Metalloid and Inorganic compounds by Nitric acid
11.3 Action of Metals & Proteins
Preparation:
(i) Laboratory Method $$KN{O_3} + conc.\,{H_2}S{O_4} \to KHS{O_4} + HN{O_3}\;(vap.)$$ vapors of nitric acid evolved are condensed in a glass receiver.
(ii) Industrial Preparation
(A) Birkeland Eyde Process or arc process
STEP 1 $${N_2} + {O_2}\mathop \to \limits_{3000^\circ C}^{[Electric\;arc]} 2NO + heat$$
STEP 2 \[NO + {O_2} \to N{O_2}\]
STEP 3 \[N{O_2} + {H_2}O \to HN{O_2} + HN{O_3}\]
STEP 4 \[HN{O_2} \to HN{O_3} + NO + {H_2}O\]
(B) Ostwald' Process
STEP 1 $$N{H_3} + {O_2}\mathop \to \limits_{3700^\circ C - 800^\circ C}^{[Pt.\;gauge]} NO + heat$$
STEP 2 \[NO + {O_2} \to N{O_2}\]
STEP 3 \[N{O_2} + {H_2}O \to HN{O_2} + HN{O_3}\]
STEP 4 \[HN{O_2} \to HN{O_3} + NO + {H_2}O\]
Physical properties:
Nitric acid usually acquires yellow colour due to its decomposition by sunlight into $NO_2$.\[4HN{O_3}\xrightarrow{{Sunlight}}4N{O_2} + 2{H_2}O + {O_2}\]
The yellow colour of the acid can be removed by warming it to $60 - 80^\circ C$ and bubbling dry air through it. It has extremely corrosive action on the sink and causes painful sores.
Chemical Properties:
(a) It is very strong acid. It exhibits usual properties of acids. It reacts with basic oxides, carbonates, bicarbonates, and hydroxides forming corresponding salts.$$\begin{equation} \begin{aligned} CaO + 2HN{O_3} \to Ca{(N{O_3})_2} + {H_2}O \\ N{a_2}C{O_3} + 2HN{O_3} \to 2NaN{O_3} + {H_2}O + C{O_2} \\ NaOH + HN{O_3} \to NaN{O_3} + {H_2}O \\\end{aligned} \end{equation} $$
(1) Sulphur is oxidized to sulphuric acid.$$S + 6HN{O_3} \to {H_2}S{O_4} + 6N{O_2} + 2{H_2}O$$
(2) carbon is oxidized to carbonic acid.$$C + 4HN{O_3} \to {H_2}C{O_3} + 4N{O_2} + 2{H_2}O$$
(3) Phosphorous is oxidized to orthophosphoric acid.$$\begin{equation} \begin{aligned} 2P + 10HN{O_3} \to 2{H_2}P{O_4} + 16N{O_2} + 4{H_2}O \\ \quad \;\;conc.\;\ \;hot \\\end{aligned} \end{equation} $$
(4) Iodine is oxidized to iodic acid.$$\begin{equation} \begin{aligned} {I_2} + 10HN{O_3} \to 2{H_2}I{O_3} + 16N{O_2} + 4{H_2}O \\ \quad \;\;conc.\;\ \;hot \\\end{aligned} \end{equation} $$
