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AnnZ [28]
3 years ago
7

How many kJ of heat are released by the reaction of 25.0 g of Na2O2(s) in the following reaction? (M = 78.0 g/mol for Na2O2)

Chemistry
1 answer:
solong [7]3 years ago
6 0

-20.16 KJ of heat are released by the reaction of 25.0 g of Na2O2.

Explanation:

Given:

mass of Na2O2 = 25 grams

atomic mass of Na2O2 = 78 gram/mole

number of mole = \frac{mass}{atomic mass of 1 mole}

                          = \frac{25}{78}

                          =0. 32 moles

The balanced equation for the reaction:

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

It can be seen that 126 KJ of energy is released when 2 moles of Na2O2 undergoes reaction.

similarly 0.3 moles of Na2O2 on reaction would give:

\frac{126}{2} = \frac{x}{0.32}

x = \frac{126 x 0.32}{2}

 = -20.16 KJ

Thus, - 20.16 KJ of energy will be released.

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