1 mol of hydrocarbon P (contains C and H only) required 240 g of oxygen (O₂​) for complete combustion at standard state. If at standard state heat of combustion of P(I) is −3350 kJ/mol while heat of formation of CO₂​( g),H₂O(I) and P(I) are −400 kJ/mol,−300 kJ/mol and 50 kJ/mol. The molar mass of P is (in g/mol )