Hydrogen peroxide decomposes to water and oxygen at constant pressure (△H = -196 kJ). What is the value of q (kJ)for this reaction when 4.60 g of hydrogen peroxide decomposes at constant pressure? A)-26.5 kJ B)-0.0189 kJ C)1.25 kJ D)-2.65 × 10⁴ kJ E)-13.3 kJ

Question

Quizplus · Accepted Answer

The molar mass of H2O2 is 34.01 g/mol. 4.60 g of H2O2 is 4.60/34.01 = 0.135 mol. The reaction releases 196 kJ per mole, so q = 0.135 mol × (-196 kJ/mol) = -26.5 kJ.

Hydrogen Peroxide Decomposes to Water and Oxygen at Constant Pressure