hydrogen peroxide can decompose to water and oxygen by the following reaction

2H2O2 (l) ------ 2H2O(l) + O2(g) enthalpy=-196kj
calculate the value of q when 5.00g of h20(l) decomposes at constant pressure.

Question

hydrogen peroxide can decompose to water and oxygen by the following reaction

2H2O2 (l) ------ 2H2O(l) + O2(g) enthalpy=-196kj
calculate the value of q when 5.00g of h20(l) decomposes at constant pressure.

rogue · Answer

5.00 g / 34 g/mol H2O2 = 0.147 mol H2O2 If the decomposition of 2 moles of H2O2 releases 196 kJ of energy, 0.147 moles of H2O2 releases 14.41 kJ (0.147 mol * 196kJ/2mol) energy. So your delta H = -14.41. Delta Q + Delta H = 0, so your delta Q = +14.41 kJ.