In a student's experiment, when 40 mL of 6% (w/w) hydrogen peroxide solution was reacted with 10 mL 0.5 M FeCl3 solution, a ΔrH of -3,382 J was calculated.

Question

Calculate ΔH for this reaction in kJ mol-1. Give your answer to 2 decimal places, do not include the units in your answer. Assume a density of 1.0 g mL-1 for the hydrogen peroxide solution.

Answer 1

this pre lab sucks

Answer 2

6% solution means 6g H2O2 per 100g of water. 1g of water = 1ml, so 6g H202/100mL. Now you have 40mL solution, so, 40mL * (6g/100mL) = 2.4g of H2O2, moles of H2O2 = 2.4/34.0147 = 0.0705 moles H2O2. ΔH = ΔrH/moles H2O2.
ΔH = -3.382kJ/0.0705mole = 47.93 kJ/mol

Answer 3

-47.93*