Problem : CaCO3(s) + 176 kJ→CaO(s) + CO2(g)

How much energy is required to decompose 10.4 moles of CaCO3(s)?

10.4 moles×176 kJ / mole = 1830 kJ

Problem : SO3(g) + H2O(l)→H2SO4(aq) +  129.6 kJ

At STP, if 540 kJ is released, what volume of SO3(g) was originally added?


=4.17 moles SO3(g)  
=93.3 L