57.0 mL 0.100 M AgNO3 57.0 mL 0.100 M HCl 22.96℃ 23.76℃ 114.0 g

57.0 mL 0.100 M AgNO3 57.0 mL 0.100 M HCl 22.96℃ 23.76℃ 114.0 g

 

 

In a coffee-cup calorimeter,

57.0 mL of 0.100 M AgNO3 and 57.0 mL of 0.100 M HCl are mixed

to yield the following reaction.

Ag^+(aq) + Cl^-(aq) → AgCl(s)

 

The two solutions were initially at 22.96℃,

and the final temperature is 23.76℃.

Calculate the heat that accompanies this reaction in kJ/mol of AgCl formed.

Assume that the combined solution has a mass of 114.0 g

and has a specific heat capacity of 4.18 J/g•℃.

 

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(0.100 mol/L) (57.0/1000 L)

= 0.00570 mol AgNO3

= 0.00570 mol HCl

 

 

 

q = C m Δt

( 참고 https://ywpop.tistory.com/2897 )

 

= (4.18 J/g•℃) (114.0 g) (23.76 – 22.96 ℃)

= (4.18) (114.0) (23.76 – 22.96)

= 381.216 J

---> 용액이 흡수한 열 (= 커피-컵 열량계로 측정한 열)

---> 반응 계가 방출한 열 = –381.216 J

( 주위가 흡수한 열 = 계가 방출한 열. 단, 부호는 반대. )

 

 

 

–381.216 J / 0.0057 mol

= –66880 J/mol

= –66.88 kJ/mol

 

 

 

답: –66.88 kJ/mol