Does anyone know how to solve this 1 Chemistry problem? I am having a hard time figuring out how to do it can someone help? THANK YOU?

[匿名]

2017-11-08 1:09 pm

1. Dissolving 5.0 g of CaCl2(s) in 150.0g of water in a calorimeter at 22.4 degree Celsius causes the temperature to rise to 27.8 degree Celsius. What is the approximate amount of heat involved in the dissolution, assuming the heat capacity of the resulting solution is 4.18 J/g degree Celsius? Is the reaction exothermic or endothermic?

Thank you for the help it means alot!

回答 (1)

micatkie

2017-11-08 4:04 pm

✔ 最佳答案

Assume that the heat capacity of the calorimeter is 0, and there is no heat loss to or heat gain from the surroundings.

Heat involved in the reaction
= Heat absorbed by the solution
= m c ΔT
= [(150.0 + 5.0) g] × [4.18 J/g °C] × [(27.8 - 22.4) °C]
= 3500 J

As the temperature of the solution raises from 22.4 °C to 27.8 °C, the solution absorbs heat in the process. The heat absorbed by the solution is that released from the solution. Hence, it can be deduced that the reaction is exothermic.

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