When 1.75g of CaCl2 dissolves in 125g of water in a coffee-cup calorimeter, the temperature increases by 2.44 degrees celsius. What is the heat change per mole of CaCl2 dissolved in water? Assume that all of the heat is absorbed by the water (c=4.18j/g deg C)
2006-11-24 03:33:30 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
The specific heat of water is 1 calorie/gram °C = 4.186 joule/gram-°C. If you want to use 4.18, that is okay.
The heat added = the specific heat of water (c) times the mass of the water (m) times the change in temperature.
Q = cmT or
= 4.18 joule/g-°C * 125 g * 2.44 °C
= 4.18 * 125 * 2.44 joules (you can do the math)
This is for 1.75 g of CaCl2 which has a molecular mass of 111.0 g/mol, so the number of moles is:
1.75 g / 111.0 g/mol = 0.01577 moles of CaCl2.
Divide the heat change (in joules) above by 0.01577 moles to get the heat per mole.
2006-11-26 06:11:50 · answer #1 · answered by Richard 7 · 71⤊ 0⤋
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2016-05-16 06:38:58 · answer #2 · answered by Anonymous · 0⤊ 0⤋
entire mass of answer=126.75g warmth absorbed via answer=C*m*deltaT=1292.75J warmth absorbed/g of chloride=738.71J warmth absorbed according to mole (111g)=82kJ that's assuming ur 'c-cup-c' absorbs no warmth and that the dil answer has comparable SHC as water
2016-12-29 10:06:52 · answer #3 · answered by dobard 3 · 0⤊ 0⤋