0.100 M AgNO3 50.0 mL 0.100 M HCl 50.0 mL 22.60℃ 23.40℃

0.100 M AgNO3 50.0 mL 0.100 M HCl 50.0 mL 22.60℃ 23.40℃

 

 

In a coffee-cup calorimeter,

50.0 mL of 0.100 M AgNO3 and 50.0 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 22.60℃,

and the final temperature is 23.40℃.

Calculate the heat that accompanies this reaction

in kJ/mol of AgCl formed.

Assume that the combined solution has a mass of 100.0 g

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

 

---------------------------------------------------

 

q = C m Δt

( 참고 https://ywpop.tistory.com/2897 )

 

= (4.18) (100.0) (23.40 – 22.60)

= 334.4 J

 

 

 

AgNO3 : Ag^+ : AgCl = 1 : 1 : 1 계수비(= 몰수비) 이므로,

AgNO3의 몰수 = AgCl의 몰수

 

 

 

(0.100 mol/L) × (50.0/1000 L) = 0.00500 mol AgCl

( 참고 https://ywpop.tistory.com/7787 )

 

 

 

334.4 J / 0.00500 mol = 66880 J/mol

= 66.88 kJ/mol

---> 1몰당 반응열

 

 

 

발열 반응이므로,

( 22.60℃ → 23.40℃ )

 

답: ΔH = –66.88 kJ/mol

 

 

 

 

[ 관련 예제 https://ywpop.tistory.com/14988 ]

0.100 M AgNO3 50.0 mL 0.100 M HCl 50.0 mL 22.30℃ 23.11℃