Chemistry (heat problem for final temperature)－飛航模式

標題:

此文章來自奇摩知識+如有不便請留言告知

Chemistry (heat problem for final temperature)

發問:

A cast iron pan sitting at room temperature on a cork trivet is filled with boiling water from a tea kettle on a nearby stove. The pan has a mass of 2.25 kg and has a 4.0 L capacity. Calculate a final temperature for the system, assuming minimal loss of engergy to the surroundings. Cp Fe = 0.449 J/g degree Celsius.

最佳解答:

Assuming all the energy from the boiling water will be transferred to the iron pan without lossing of energy. Let T be the final temperature and the Cp water = 4.2 J/g and assuming room temp = 25C The energy from the boiling water transferred to the iron pan is: Ewater = 4000g x 4.2 x (100 -T) The energy received by the iron pan will be: Epan = 2250 x 0.449 x (T - 25) Since no energy loss, E water = E pan 4000x 4.2 x (100 - T) = 2250 x 0.449 x (T-25) 1680000 - 16800T = 1010.25T - 25256.25 17810.25T = 1705256.25 T = 95.746 C Therefore,the final temperature of the system will be 95.746C.

其他解答:554581090DCCD3AC