155.0 g Cu 150.0℃ 19.8℃ water 250.0 g 0.385 J/g•℃

155.0 g Cu 150.0℃ 19.8℃ water 250.0 g 0.385 J/g•℃

 

 

A 155.0 g piece of copper at 150.0℃

is dropped into 250.0 g of water at 19.8℃.

(the specific heat of copper is 0.385 J/g•℃.)

Calculate the final temperature of the mixture.

(assume no heat loss to the surroundings.)

 

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q = C m Δt

( 참고 https://ywpop.tistory.com/2897 )

 

 

 

최종 온도를 x라 두면,

고온 물질이 잃은 열(-q) = 저온 물질이 얻은 열(+q)

-[(0.385 J/g•℃) (155.0 g) (x – 150.0 ℃)

= +[(4.184 J/g•℃) (250.0 g) (x – 19.8 ℃)]

 

-59.675x + 8951.25 = 1046x – 20710.8

1105.675x = 29662.05

x = 29662.05 / 1105.675 = 26.8℃

 

 

 

[ 관련 예제 https://ywpop.tistory.com/15482 ] 7 kg, 600℃ 구리 + 20℃, 8 kg 물