6th edition, 8.53

[Hai-Lin Yeh 1J]

8;53 The reaction of 1.40 g of carbon monoxide with excess water vapor to produce carbon dioxide and hydrogen gases in a bomb calorimeter causes the temperature of the calorimeter assembly to rise from 22.113 C to 22.799 C. The calorimeter assembly is known to have a total heat capacity of 3.00 kJ·(C-1). (b) Calculate the internal energy change, deltaU, for the reaction of 1.00 mol CO(g). Can someone explain why we do not use 1.00 mol CO (g) and we use 1.40 g instead? Isn't the reaction for 1.00 mol CO?

[Chem_Mod]

The 1.4 g of CO is less than 1 mol, so you want to find the reaction enthalpy of using 1.4 g of CO and then figure out what the enthalpy is if 1 mol of CO is reacted.

[Hai-Lin Yeh 1J]

But in the answer key, they only used 1.40 g. It never mentions 1.00 mol CO. So why do we disregard 1.00 mol?