The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s) + O₂ (g) → 2BaO (s)
How many kJ of heat are released when 15.75 g of Ba (s) reacts completely with oxygen to form BaO (s) ?

Question

The value of ΔH° for the reaction below is -1107 kJ: 2Ba (s)+ O₂ (g)→ 2BaO (s) How many kJ of heat are released when 15.75 g of Ba (s)reacts completely with oxygen to form BaO (s)?

Quizplus · Accepted Answer

First, we need to find the moles of Ba used in the reaction:

15.75 g Ba * (1 mol Ba / 137.33 g Ba) = 0.1143 mol Ba

According to the balanced equation, 2 moles of Ba produce -1107 kJ of heat. Therefore, 0.1143 mol Ba produces:

(-1107 kJ / 2 mol Ba) * 0.1143 mol Ba = -63.5 kJ

The negative sign indicates that heat is released (exothermic reaction). Therefore, the correct answer is B.

The Value of ΔH° for the Reaction Below Is -1107