39. The volumes of 4 N HCl and 10 N HCl required to make 1 litre of 6 N HCl are

a. 0.75 litre of 10 N HCl  and 0.25 litre of 4 N HCl

b. 0.25 litre of 4 N HCl  and 0.75 litre of 10 N HCl

c. 0.67  litre of 4 N HCl  and 0.33 litre of 10 N HCl

d. 0.80 litre of 4N HCl  and 0.20litre of 10 N HCl

e. 0.50litre of 4 N HCl  and 0.50litre of 10N HCl

Ans. c