Question

1. How much heat is released when 9.22 grams of glucose C6H12O6 reacts according to the following equation?
C6H12O6 + 6O2 --> 6CO2 + 6H2O ∆H = -2803 kJ

2. How much heat is absorbed during photosynthesis when 9.22 grams of glucose C6H12O6 is produced?
6CO2 + 6H2O --> C6H12O6 + 6O2 ∆H = +2803 kJ

3. How much heat is released when 147 grams of NO2(g) is dissolved in excess water?
3NO2 + H2O --> 2HNO3 + NO ∆H = - 138 kJ

4. Calculate the heat released when 74.6 grams of SO2 reacts according to the following equation.
2SO2 + O2 --> 2SO3 ∆H = -99.1 k

Answer 1

1. molar mass glucose is 180 g/mol. 2803 kJ energy released every 180 grams. So for 9.22 g it will be 2803 x (9.22/180) = ? released.
2. The reverse reaction absorbs the same amount; ie. 2803 x (9.22/180) = ?
3 and 4 are done the same way. I'll be happy to check your work if you will post your work, not just the answers.