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How much heat in kJ is released when 0.677 mol NaOH(soln) is dissolved in water? (ΔH(soln) = –44.5 kJ/mol for NaOH)NaOH(s) rightwards arrow Na+(aq) + OH–(aq) + 44.5 kJ/mol

User Rehan
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1 Answer

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16 votes

Step-by-step explanation:

The dissolution reaction of NaOH is:

NaOH (s) -----> Na⁺ (aq) + OH⁻ (aq) + 44.5 kJ/mol

ΔH(soln) = –44.5 kJ/mol

This reaction is exothermic, because the ΔH is negative. That's why the 44.5 kJ/mol appears in the products side, because heat is being released.

From the ΔH of solution we know that 1 mol of NaOH will realease 44.5 kJ when it dissolves. We have to find the heat released by 0.677 mol of NaOH.

Heat released = 0.677 moles * (-44.5 kJ/mol)

Heat released = - 30.1 kJ

Answer: -30.1 kJ is released when 0.677 mol of NaOH is dissolved.

User Elbimio
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