the heat of combustion of stearic acid is -11300 kj/mol. the molar mass of the acid is 284.5 g/mol. When 1.22 g of the acid is burned in a calorimeter, with heat capacity of 3.21 kj/degree celcius. what is the temp. increase of the calorimeter?
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and also if u can do this one, it would be helpful.
2) KCLO3 (s) ----> KCLO3 (aq) Change in H is +41.4 kj/mol
how many grams of potassium chlorate have to be dissolved in water (total mass of solution 100g) to decrease the temperature by 5 celcius? Assume the specific heat capacity of the solution is 4.18 J/g celcius. The molar mass of potassium chlorate is 122.6 g/mol.
I have no idea of what to do.!!!! plz help
and also if u can do this one, it would be helpful.
2) KCLO3 (s) ----> KCLO3 (aq) Change in H is +41.4 kj/mol
how many grams of potassium chlorate have to be dissolved in water (total mass of solution 100g) to decrease the temperature by 5 celcius? Assume the specific heat capacity of the solution is 4.18 J/g celcius. The molar mass of potassium chlorate is 122.6 g/mol.
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Stearic acid is C17H35COOH. Its molar mass = 284.5
1.22 g / 284.5 = 0.004288 mole
Heat of combustion of 0.004288 mole of stearic acid is -48.45 kj
Heat capacity of calorimeter = 3.21 kj/deg C
48.45 / 3.21 = 15.1 deg C
TEMP INCREASE = 15.1 deg C
4.18 j/gC x 5 C x 100 g = 2090 j
41400 j/mol / 122.6 g/mol = 337.7 j/g
2090 /37.7 = 6.19 g KClO3
1.22 g / 284.5 = 0.004288 mole
Heat of combustion of 0.004288 mole of stearic acid is -48.45 kj
Heat capacity of calorimeter = 3.21 kj/deg C
48.45 / 3.21 = 15.1 deg C
TEMP INCREASE = 15.1 deg C
4.18 j/gC x 5 C x 100 g = 2090 j
41400 j/mol / 122.6 g/mol = 337.7 j/g
2090 /37.7 = 6.19 g KClO3