Download 1st law of thermodynamic

1ST LAW OF
THERMODYNAMIC
2 ND T U T O R I A L
1) In each of the following situations, find the change
in internal energy of the system.
a)A system adsorbs 500 cal of heat at the same time
does 400J of work.
b)A system adsorbs 300 cal and the same time 420J
of work is done on it.
c)Twelve hundred calories is removed from a gas
held at constant volume
2) The temperature of 3 moles of a monoatomic ideal
gas is reduce from 540k to 350k as 5500J of heat flows
into the gas. Find;
a)The change in initial energy?
b)The work done by the gas?
3) The initial temperature of 150g of ethanol was 22
deg celsius. What will be the final temperature of the
ethanol of 3240J was needed to raise the
temperature of the ethanol?
• (special heat capacity of ethanol is 2.44 J°C-1g-1)
4) Calculate the internal energy, U when 1.00 mol of
H20 goes from 25.5°C and 1.00 atm to 30.0°C and
1.00 atm. Densities of water are 0.9970 g/cm3 at 0°C
and 0.9956 g/m3 at 100°C.
5) A cylinder fitted with a friction piston contains 3.00
mol of He gas at P=1.00 aym and is in a large
constant temperature bath at 400k. The pressure is
reversible increase to 5.00 atm. Find w, q and U for
the process.
6) If P1= 3.00 atm, V1=500 cm3, P2= 1.00 atm and
V2=2000 cm3. Calculate the work, Wrev for process
shown in figure (a) and (b).
7) Gas expands by 1.2L at a constant pressure of
2.5x105 Pa. During the expansion, 500J of heat is
added. Find the change in the internal energy of the
gas. Draw a PV diagram with your solution.
8) A sample containing 1000 moles of nearly ideal
monoatomic gas is put through the cycle of
operations shown to the right. BC is an isothermal,
and PA=1.00 atm, VA = 22.4 m3, PB=2.00 atm.
a)What is TA, TB and VC?
b) What is the work done over each process?
c) What is the total work done in one cycle?
•THANK YOU