Question

If 250 kj of energy are absorbed in the following reaction, how many moles of co2 reacted:

Answer 1

Answer:

.54 mol

Explanation:

Using the ΔH given for the balanced reaction, convert kilojoules to moles of  CO2 using the stoichiometric ratio:

250 kJ×(6 moles CO22803 kJ)=0.5351 moles CO2

The answer should have two significant figures, so round to 0.54 moles CO2.

Notice that coefficients in stoichiometric equations (indicating numbers of moles) are exact, so they do not constrain the number of significant figures.