Question

27) What volume of benzene (C6H6, d= 0.88 g/mL, molar mass = 78.11 g/mol) is required to produce 1.5 x 103 kJ of heat according to the following reaction?
2 C6H6(l) + 15 O2(g) ¨ 12 CO2(g) + 6 H2O(g) ƒ¢H‹rxn = -6278 kJ

Answer 1

The reaction you show is for two moles benzene. Since the molar mass is 78.11 g/mole, then 2 moles is 2 x 79.11 = 156.22 grams. Thus 156.22 g benzene will produce 6278 kJ of heat. You want to produce 1500 kJ. Use proportions to determine the mass of benzene needed, then use density = mass x volume to convert to volume. Post your work if you get stuck.

Answer 2

37.326 g