71.
Carborundum is another name of

72.
German silver is an alloy of

73.
Which one of the following does not contain Silver ?

74.
Type metal used in printing press is an alloy of

75.
Ultra purification of a metal is done by :

76.
Brass gets discoloured in air due to constant exposure in presence of:

77.
Which of the following is not present in German silver?

78.
Haloarenes are more stable than haloalkanes due to

79.
The unit of ionic product of water (Kw) is :