The chiefsource for the production of nitrogeneous fertilizers is :
1). Ammonia
2). Nitric acid
3). Nitrogen
4). Nitrogen dioxide
Silver halides are used in photographic plates because they are
1). oxidised in air
2). soluble in hyposolution
3). reduced by light
4). totally colourless
White phosphorus is always kept under
1). benzene
2). kerosene
3). ether
4). water
Tear gas used by the police to disperse the mob contains
1). Carbon dioxide
2). Chlorine
3). Ammonia
4). Hydrogen sulphide
Fermentation of milk to curd is due to :
1). Mycobacterium
2). Staphylococcus
3). Lactobacillus
4). Yeasts