0.800 M H2SO4 25.0 mL + NaOH 50.0 mL 25.00℃ 32.14℃

0.800 M H2SO4 25.0 mL + NaOH 50.0 mL 25.00℃ 32.14℃

 

 

25.0 mL of an aqueous 0.800 M solution of H2SO4

was added to 50.0 mL of an aqueous solution of NaOH,

which was in excess, contained in a coffee cup calorimeter.

The two solutions and the calorimeter are initially at 25.00℃.

H2SO4 + 2NaOH → Na2SO4 + 2H2O

 

After completion of the reaction,

the temperature of the solution is 32.14℃.

Calculate the ∆H for this reaction in kJ/mol.

 

Assume the density and specific heat of the final solution

are the same as for water

(density = 1.00 g/mL and specific heat = 4.184 J/g•℃),

and the calorimeter itself absorbs no heat.

 

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q = C m Δt

( 참고 https://ywpop.tistory.com/2897 )

 

= (4.184 J/g•℃) (25.0 + 50.0 g) (32.14 – 25.00 ℃)

= 2240.5 J

 

 

 

(0.800 mol/L) (25.0/1000 L) = 0.02 mol H2SO4

= 0.04 mol H^+

 

 

 

remember 중화 반응의 본질

H^+ + OH^- → H2O

 

 

 

-2240.5 J / 0.04 mol

= -56012.5 J/mol

= -56.0 kJ/mol

---> 즉, H2O 1 mol당 중화열.

 

 

 

답: ∆H = -56.0 kJ/mol

 

 

 

 

[키워드] H2SO4 + NaOH 중화열 기준문서