How is sodium chromate converted into sodium dichromate in the manufacture of potassium dichromate from chromite ore?

Options

A. By the action of concentrated sulphuric acid
B. By roasting with soda ash
C. By the action of sodium hydroxide
D. By the action of lime stone

Answer

A

Explanation

By the action of concentrated `H_2SO_4`
`underset("Sodium chromate")(2Na_2CrO_4) + underset("Conc.")(H_2SO_4) to underset("Sodium dichromate")(Na_2Cr_2O_7) + Na_2SO_4 + H_2O`