Why is hot concentrated sulphuric acid not used in the preparation of hydrogen?

A small piece of calcium metal is put into a small trough containing water. There is effervescence and white turbidity is formed.

(a) Name the gas formed in the reaction. How would you test the gas?

(b) Write an equation for the reaction.

(c) What do you observe when a few drops of red litmus solution are added to the turbid solution?

Thin strips of magnesium, copper and iron are taken.

(a) Write down what happens when these metals are treated as follows

(i) Heated in presence of air

(ii) Heated with dil. HCl

(iii) Added to an aqueous solution of zinc sulphate

(b) Arrange these metals in descending order of reactivity.

Hydrogen is manufactured by 'Bosch Process'.

(a) Give the equations with conditions.

(b) How can you obtain hydrogen from a mixture of Hydrogen and carbon monoxide?