PHYSICAL CHEMICAL PROPERTIES CHILE SALTPETRE METHOD (By NaNO3/KNO3) BRIKLAND EYDE’S METHOD BY USING AIR OSTWALD ’S METHOD BY AMMONIA SOLVEY PROCESS

1. Nitric acid
Preparation & Uses

2. CONTENTS
• INTRODUCTION
• PHYSICAL PROPERTIES
• CHEMICAL PROPERTIES
• USES
• MANUFACTURING
• PROCESS FLOW DIAGRAM

3. Introduction
• Nitric acid (HNO3).
• A colorless liquid
• Manufacture of inorganic and organic nitrates and nitro compounds
• Fertilizers, like Ca(NO3)2, NH4 NO3, dye intermediates, explosives,TNT
• Continued exposure to vapor may cause chronic bronchitis; chemical pneumonitis
• Known as (Aqua Fortis)
• NITRIC ACID, RED FUMING is a pale yellow to reddish
• Suffocating odor. Very toxic by inhalation.
• Corrosive to metals or tissue.

4. PHYSICAL CHEMICAL PROPERTIES
• It is a strong, monoprotic acid and is almost completely ionized in aqueous
solutionPhysical Properties:
• Molar mass: 63g/mol
• Color: Pure nitric acid is a colorless liquid but commercial nitric acid may be yellowish
brown due to presence of dissolved nitrogen dioxide.
• Odour: Nitric acid is a fuming, hygroscopic liquid, the fumes of which fumes gives it a
choking smell.

5. Cont…
• Acidity: Nitric acid is a very strong acid and dissociates very highly, and is very corrosive.
• Nitric Acid’s Dissociation Constant is 28 (Ka value)
• Taste: It is sour in taste due to acidic nature
• Density: Its density is 1.513 g cm-3 at 20oC.
• Boiling point: Pure nitric acid boils at 86oC.
• Melting point: When cooled below 0oC nitric acid freezes to a white
solid, which melts at - 42oC.
• Solubility: It is soluble in water in all proportions.

6. Cont…
• Reactions with metals: Nitric acid dissolves most metals including iron, copper, and silver, with
generally the liberation of lower oxides of nitrogen rather than hydrogen. It can also dissolve the noble metals
with the addition of hydrochloric acid.
Cu + 4HNO3 → Cu(NO3)2 + 2NO2 + 2H2O
• Reactions with nonmetals: Reaction with non-metallic elements, with the exception of
silicon and halogen, usually oxidizes them to their highest oxidation states as acids with the
formation of nitrogen dioxide for concentrated acid and nitrogen oxide for dilute acid.
C + 4HNO3 → CO2 + 4NO2 + 2H2O

7. MANUFACTURING OF NITRIC ACID
• OSTWALD ’S METHOD BY AMMONIA SOLVEY
PROCESS

8. CHILE SALTPETRE METHOD
(By NaNO3)
Raw material:
• Basis: Nitric acid (95% yields), Sodium Nitrate, Sulfuric acid
• Process
• The decomposition of sodium nitrate (Chili saltpetre) still remains one of the most important processes for the manufacture
of nitric acid. The complete reaction shown by the equation
2NaNO3 + H2SO4 = Na2SO4 + 2HNO3
at a relatively low temperature (200° C.),
The plant consists of
• a retort,
• condenser,
• receiver, and
• absorbing system for the oxides of nitrogen.

9. In lab pre…

11. BRIKLAND EYDE’S
METHOD
(Arc Process)
Raw materials and Process
• Air
Process
• Arc furnace
N +O ——–> NO
• Oxidizing tower
Gaseous mixture is passed in oxidizing tower where NO is oxidized into NO 2.
2NO +O2 ——–> 2NO2

12. Absorption tower :
NO2 is absorbed in water in absorption tower then dilute HNO 3 is obtained.
3NO2 + H2O ——-> 2 HNO3 + NO
Now HNO3 is not manufactured by this method because consumption of electricity is very high to maintain
temperature 3000 C. Even at this temperature 1% NO is form.
BRIKLAND EYDE’S
Reaction

15. OSTWALD’S METHOD
Principle :
NH3 is oxidized into NO by air at 800 C in presence of Pt (Platinum)catalyst.
PROCESS:
Mixture of NH3 and O2 in the ratio of 1:9 is passed through catalyst chamber containing Pt- gauge. Temperature of the catalyst is kept at 800 C.
About 95 % NH3 is converted into NO.
4NH3 + 5 O2 ——–> 4NO + 6 H2O

16. OSTWALD’S METHOD
PROCESS
Oxidizing tower
Heat liberated maintains the temperature of the catalyst. The gases coming out are cooled to about 50 C and mixed with more O2. This gaseous
passed in oxidizing tower where NO is oxidized to NO 2.
2NO + O2 ——> 2NO 2
NO2 is passed in absorption tower. The dilute solution of HNO 3 is obtained.
3NO2 + H2O ——> 2HNO 3 + NO

18. USES:
• As a starting material in the manufacture of nitrogen fertilizers such as
ammonium nitrate & ammonium etc. Large amounts are reacted with ammonia
to yield ammonium nitrate.
• It is commonly used in science laboratories at schools for experimenting when
specifically testing for chloride
• As a nitrating agent in the preparation of explosives such as TNT, nitroglycerine,
cellulose poly-nitrate, ammonium picrate.
• It is used as a medicine to remove chancres and warts.
• Used in fibers, plastics and dyestuffs industries
• Used in metallurgy and in rocket fuel production.
• It is used in calorimetric test to distinguish between heroin and morphine.

19. By Sumama Shakir
BS Chemistry
Nitric Acid