5.0 g KOH 56.1 g/mol 100.0 g water 11.6℃

5.0 g KOH 56.1 g/mol 100.0 g water 11.6℃

 

 

5.0 g of potassium hydroxide (molar mass 56.1 g/mol)

dissolves in 100.0 g of water

and the temperature of the solution increases by 11.6℃.

Calculate the ΔH_soln for potassium hydroxide.

Assume the specific heat capacity of the solution is 4.2 J/g•℃

 

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q = C m Δt

( 참고 https://ywpop.tistory.com/2897 )

 

= (4.2) (5.0 + 100.0) (11.6)

= +5115.6 J

---> 용액이 흡수한 열

---> 5.0 g KOH가 방출한 열 = –5115.6 J

 

 

 

1 mol KOH가 방출하는 열을 계산하면,

–5115.6 J / (5.0/56.1 mol)

= –57397 J/mol

= –57 kJ/mol

 

 

 

 

[키워드] KOH의 용해열 기준문서