posted by Thomas
Check my work & answer please. I need to make sure I am able to do this type of problem correctly.
A typical car engine produces 44,000 kJ of heat in an hour. The cooling system has a capacity of 8.40 L and is filled with a 50:50 mixture of anti-freeze (specific heat capacity of 8.37 J/g-oC, density of 1.038 g/mL). In maintaining a constant engine temperature, the cooling system temperature increased from 95oC to 110oC. (Assume this is within allowable limits.) How many times did the cooling system turn over its volume of anti-freeze to maintain the engine temperature during its hour of operation? Show your work. (Assume that only the cooling system removes heat from the engine and no other mechanism of heat removal is involved.)
Q = mct
44000000 = m*8.37*15
M = 350,457.984866587
1.038 = 350,457.984866587/v
Mass/d = volume
350,457.984866587/1.038 = 337,628.116442ml
That looks ok to me but you're not allowed that many significant figures. If it were me I would round to 40.2 times.