Grade 12 Chemistry (Energy)

Question

when 0.0200 mol of solid calcium oxide is dissolved in sufficient water 650 J of energy is released.

How much energy would be released if 3g of the solid was dissolved?

Answer 1

First let's determine the number of moles in 3 g of CaO. 1 mole CaO / 56.08 g x 3 g = 0.0535 moles CaO.

If 0.02 moles CaO produces 650 j then 0.0535 moles would produce 650j / 0.02 moles x 0.0535 moles =

1740 j released to 3 sig figs.