Answer :
Alright, to calculate the amount of heat required to decompose 1.28 mol of baking soda (NaHCO3) using the given thermochemical equation:
2 NaHCO3 (s) + 129 kJ → Na2CO3 (s) + H2O (l) + CO2 (g)
We can set up a proportion to find out how much heat is required for 1.28 mol of NaHCO3:
1.28 mol NaHCO3 / 2 mol NaHCO3 = x kJ / 129 kJ
Solving for x:
x = 1.28 mol * 129 kJ / 2 mol
x = 165.12 kJ / 2
x = 82.56 kJ
So, approximately 82.56 kJ of heat is required to decompose 1.28 mol of baking soda.