Nitric Acid: one laboratory method ofpreparation of nitric acid from potassiumnitrate or sodium nitrate. Large scalepreparation. Nitric acid as an oxidizing agent. Laboratory preparation of nitric acidfrom potassium nitrate or sodium nitrate;the laboratory method to be studied interms of reactants, products, conditions,equations, setting up of apparatus,diagram, precautions, collection andidentification. Manufacture of Nitric acid by Ostwald’sprocess (Only equations with conditionswhere applicable). As an oxidising agent: its reaction withcopper, carbon, sulphur.

Nitric Acid: one laboratory method of preparation of nitric acid from potassium nitrate or sodium nitrate. Large scale preparation. Nitric acid as an oxidizing agent.

Step 1: Laboratory preparation of nitric acid from potassium nitrate or sodium nitrate:

• Reactants: Potassium nitrate (KNO3) or sodium nitrate (NaNO3)
• Products: Nitric acid (HNO3)
• Conditions: The reaction is carried out in the presence of concentrated sulfuric acid (H2SO4) as a catalyst.
• Equation: KNO3 + H2SO4 → KHSO4 + HNO3

Step 2: Setting up of apparatus:

• A round-bottom flask is connected to a condenser and a receiver.
• The round-bottom flask contains the mixture of potassium nitrate or sodium nitrate and concentrated sulfuric acid.
• The condenser is attached to the round-bottom flask to condense the nitric acid vapors.
• The receiver collects the condensed nitric acid.

Step 3: Precautions:

• The reaction should be carried out in a well-ventilated area or under a fume hood due to the release of toxic fumes.
• Safety goggles and gloves should be worn to protect against any potential hazards.

Step 4: Collection and identification:

• The nitric acid vapors are condensed in the condenser and collected in the receiver.
• The collected nitric acid can be identified by its characteristic yellow color and pungent odor.

Manufacture of Nitric acid by Ostwald’s process:

• Equations with conditions:

1. Ammonia oxidation: 4NH3 + 5O2 → 4NO + 6H2O
   • Conditions: High temperature (800-900°C) and a platinum catalyst.
2. Nitric oxide oxidation: 2NO + O2 → 2NO2
   • Conditions: High temperature (400-500°C) and a platinum catalyst.
3. Absorption of nitrogen dioxide: 3NO2 + H2O → 2HNO3 + NO
   • Conditions: Absorption of nitrogen dioxide in water.

As an oxidizing agent: its reaction with copper, carbon, sulfur.

• Reaction with copper: 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O
• Reaction with carbon: 4HNO3 + C → CO2 + 2H2O + 4NO2
• Reaction with sulfur: 6HNO3 + S → H2SO4 + 6NO2 + 2H2O