Ethanol can be made from ethanal using sodium tetrahydridoborate(III) as a reducing agent.

a. Give the formula of sodium tetrahydridoborate(III).

b. What other reagent is necessary for the reaction to take place?

c. The reaction mechanism proceeds in a similar way to the steps in the reaction of ethanal with HCN, but the initial attack is by the ^H– ion instead of the CN^– ion. The intermediate then gains an H⁺ ion from a water molecule to form the product, ethanol. Name the mechanism and describe it as fully as you can, using curly arrows to show the movement of electron pairs.