Which one of the following processes involves a chemical reaction ? [1]
A. storing of oxygen gas under pressure in a gas cylinder
B. liquification of air
C. keeping petrol in a chinadish in open
D. heating copper wire in presence of air at high temperature
Answer:D
Which one of the following processes involves a chemical reaction ? [1]
A. storing of oxygen gas under pressure in a gas cylinder B. liquification of air C. keeping petrol in a chinadish in open D. heating copper wire in presence of air at high temperature