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Maurinko [17]
3 years ago
5

125.0 g of an unknown substance is heated to 97.0°C. It is then placed in a calorimeter than contains 250g of water with an init

ial temperature of 20.0°C.
The final temperature reached by the calorimeter is 23.5°C.
What is the specific heat of the unknown substance? The specific heat of water is 4.18 J/ (°C × g)

A) 0.285 J/ (°C × g)
B) 0.398 J/ (°C × g)
C) 0.729 J/ (°C × g)
D) 1.24 J/ (°C × g)
Chemistry
2 answers:
rodikova [14]3 years ago
5 0

Answer:

Answer is B

Explanation:

Sveta_85 [38]3 years ago
4 0
The heat released by the substance in the calorimeter is equal to  the heat absorbed by water which results to the decrease and increase in temperature, respectively.
We use m Cp ΔT to balance the heat involved 

(m Cp ΔT) subs in calorimeter = <span>(m Cp ΔT) water
</span>125 g * Cp * (97.0-23.5 ) C = 250 g *(4.18 J/C g)* (23.5-20)
Cp = 0.398 J/Cg

Answer is B 
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