Problem: For the following reaction, what is ∆H° when 25.0 g of Na2O2(molar mass = 77.98 g mol−1) is reacted with water?2 Na2O2(s) + 2 H2O(l) → 4 NaOH(s) + O2(g)         ∆H° = −126 kJ(A) -20.2 kJ (B) 87.4 kJ (C) -126 kJ (D) 20.2 kJ (E) -87.4 kJ

FREE Expert Solution

Use the concept of thermochemistry and stoichiometry to determine ΔH of the reaction of 25 g Na2O2 upon reaction with water

It can be seen that 2 moles of Na2O2 produces -126 kJ of heat.

Calculating for the ΔH of the reaction:

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Problem Details

For the following reaction, what is ∆H° when 25.0 g of Na2O2(molar mass = 77.98 g mol−1) is reacted with water?

2 Na2O2(s) + 2 H2O(l) → 4 NaOH(s) + O2(g)         ∆H° = −126 kJ

(A) -20.2 kJ 

(B) 87.4 kJ 

(C) -126 kJ 

(D) 20.2 kJ 

(E) -87.4 kJ