In this question, we have the following reaction:
A. C + 2 Cl2 -> CCl4, this is the full reaction, the product is Carbon tetrachloride
B. According to the molar ratio between the product and the 2 reactants, we have 1 mol of CCl4 for 1 mol of C and 1 mol of CCl4 for 1 mol of Cl2, therefore if we have 3 moles of CCl4, we will need 3 times more moles of the reactants, the final reaction will be:
3 C + 6 Cl2 -> 3 CCl4
