View Full Version : Find kilojoules
hslove142331
Jan 25, 2010, 09:55 PM
The molar heat of vaporization of carbon disulfide, CS2, is 28.4 kJ mol-1 at its boiling point. How many kilojoules of heat would be liberated by the condensation of 6.57 g of carbon disulfide?
How can I find kilogules?
Any equations?
Thank you..
Unknown008
Jan 26, 2010, 08:10 AM
The compiound takes 28.4 kJ/mol on boiling.
Therefore, it releases 28.4 kJ/mol on condensing. (reverse process)
Find the number of moles you have in 6.57 g and use proportions to find the heat release upon condensation.
hslove142331
Jan 27, 2010, 02:29 PM
I got 11.56moles... and how can I do next?
Unknown008
Jan 28, 2010, 07:08 AM
1 mole of CS2 weighs (12+32+32) = 76 g
Or;
76 g of CS2 contains 1 mole.
1 g of CS2 contains 1/76 mole
6.57 g of CS2 contains (1/76)*6.57 = 0.0864 mol
Now, 1 mole releases 28.4 kJ
0.0864 mol will release (28.4*0.0864) = 2.46 kJ.