Question

please help me with problems 3 and 4

3. A sample of nitrogen gas expands in volume from 2.2 L to 4.6 L at constant temperature Calculate the work done in joules if the gas expands against: a. a vacuum. b. a constant pressure of 0.65 atm. c. a constant pressure of 2.7 atm. 4. Consider the following data: Metal Mass (g) Specific Heat, J/g °C Temperature, °C do these two metals are placed in contact, which of the following will take place? Al Cu 10 30 0.900 0.285 40 60 icis a. Heat will flow from Al to Cu because Al has a larger specific heat. b. Heat will flow from Cu to Al because Cu has a larger heat capacity. c. Heat will flow from Cu to Al because Cu is at a higher temperature. d. Heat will flow from Cu to Al because Cu has a larger mass. e. No heat will flow in either direction.

Answer 1

Q-3 ) ( a ) work will be zero since P_ext =0

( b ) Q -4) correct option is c since heat flow from high temperature body to low temperature body.

Av : 4.6 -2.25 2.417- (6) w= -Pext (12-2) = -0.65 atm x 2.4 it! atmalt x 1013 J = -0.6582.4 1 (t-athm = -158.028 J leo w = -2.7 atm x 2.4 14 3. atm-ltx 101-3 J - -2-782-4 1 athalt = -656.42 J