In one experiment x grams of CS2 is mixed with y grams of NaOH. The reaction is represented by the unbalanced equation below.

CS2 + NaOH  Na2CS3 + Na2CO3 + H2O

At the end of the reaction, 7.5 g of Na2CO3 is formed while 3.3 g of CS2 is left unreacted in the reaction vessel. All the NaOH in the vessel is completely consumed.

a) Balance the above equation
b) Calculate the amount of CS2 (x grams) and NaOH (y grams) added to the reaction vessel at the beginning of the reaction.​