Answer:
-8.64kJ
Step-by-step explanation:
Based on the reaction:
2 H₂O₂(l) → 2 H₂O(l) + O₂(g) ΔH = -196 kJ
When 2 moles of hydrogen peroxide (H₂O₂) descomposed, there are released -196kJ of energy.
Now, if 3,00g of hydrogen peroxide react, moles are:
3.00g × (1mol / 34.01g) = 0.0882moles H₂O₂
Releasing:
0.0882moles H₂O₂ × (-196kJ / 2mol H₂O₂) = -8.64kJ