Select the incorrect statements.
I. In railway tracks, space is left between two rails
at the joint to allow for the expansion of iron rails
during winter.
II. For gases, solubility in water decreases with rise
in temperature.
III. When mercury thermometer is used to measure
the temperature, a chemical change takes place.
IV. At a particular temperature, the amount of salt or
sugar that can be dissolved in 100 mL of water is
same.
V. Galvanisation involves a physical change.
A I and II only
B III and V only
C I, III, IV and V only
D I, II, III, IV and V
Ans 1:
Class : Class 7
Galvanization is the process of applying a protective zinc coating to steel or iron surface, to protect it from rusting. The steel parts are submerged in a bath of molten zinc. While steel is immersed in zinc, a metallurgical reaction occurs between the iron in the steel and the molten zinc. So, this is a chemical process.