A bomb calorimeter has a heat capacity of 843 J/°C and contains 473 g of water. If the combustion of 0.500 mole of a hydrocarbon increases the temperature of the calorimeter from 22.73°C to 26.95°C, determine the heat evolved per mole of hydrocarbon.
A. 8.38 kJ
B. 23.8 kJ
C. 76.0 kJ
D. 95.9 kJ
E. 8380 kJ
2007-10-28 06:30:37 · 3 answers · asked by desigoddess217 1 in Science & Mathematics ➔ Chemistry
If the water was at 22.73C, then the calorimeter was too. Likewise the end temperature for both. 26.95C - 22.73C = 4.22degC difference. So first heat the calorimeter:
4.22degC x 843J/degC = 3557 J
Next heat the water:
473gH2O x 4.22degC x 4.184J/g-degC = 8351 J
3557J + 8351J = 11910 J to four sig figs.
11910J/0.500molH = 23,820 J/mol, which is B.
2007-10-28 06:56:12 · answer #1 · answered by steve_geo1 7 · 1⤊ 0⤋
Heat evolved= Heat Capacity * Temperature difference
So Heat evolved per mole= (843 J/Deg C * ( 26.95-22.73))/0.5= 7.114 KJ / mole
2007-10-28 07:04:07 · answer #2 · answered by ATOZ 2 · 0⤊ 1⤋
A calorimeter is a device used for calorimetry, the science of measuring the heat of chemical reactions or physical changes as well as heat capacity. The word calorimeter is derived from the Latin word calor, meaning heat. A simple calorimeter just consists of a thermometer attached to a metal container full of water suspended above a combustion chamber.
2016-04-10 23:21:34 · answer #3 · answered by Anonymous · 0⤊ 0⤋