Posted by Mary on .
Three moles of an ideal monatomic gas are at a temperature of 345 K. Then, 2531 J of heat are added to the gas, and 1101 J of work are done on it. What is the final temperature of the gas?
delta U= 3/2nR(T final T initial)
(2531J  1101J) = 3/2(3.0mol)(8.31)(T final  345K)
1430J = 37.395(T final  345K)
1430J/ 37.395 = T final  345K
38.24 + 345K = T final
383.2404K = T final
This answer is incorrect. Please explan to me where I went wrong.
if work was done on it, wouldn't the internal energy go up, and therefore the work ADDED to the heat added? Maybe I don't understand your statement.

Physics please check 
kat,
since work is done on the gas, the value of work has to be negative. so you would do 2531 + 1101 instead