Normally pure substance and reagents are used in chemical reactions. Explain why in the preparation of dihydrogen by actiion of dilute sulphuric acid on zinc metal, impure zinc is preferred?

Normally pure substance and reagents are used in chemical reactions. E

1.	Normally pure substance and reagents are used in chemical reactions. Explain why in the preparation of dihydrogen by actiion of dilute sulphuric acid on zinc metal, impure zinc is preferred?
Answer» Solution :Pure Zinc is not use in the preparation of dihydrogen because its reaction with dilute `H_(2)SO_(4)` is slow. The reason being that initially formed GASEOUS hydrogen forms an EXTREMELY then film on the surface of zinc which prevents further actioin of zinc with acid. However, the presence of impurities in zinc increases the RATE of reaction due to the formation of ELECTROCHEMICAL CELLS.