Answer :
15 liters H2O = 15*1000g = 15,000 grams
heat needed to raise one gram water, one degree celsius = 4.18J
4.18J * 15,000g = 62,700J = 62.7kJ needed per degree C
85 - 22 = 63C temp drop needed
62.7 kJ * 63C = 3950.1kJ needed from CO2
enthalpy of CO2 = 393.51kJ/mol
CO2 = 44g/mol = 22.73 moles/kg
393.51kJ/mol * 22.73 moles/kg
= 8,943.4 kJ/kg
3950.1kJ / 8,943.4 kJ/kg = .4417 kg of CO2 needed
heat needed to raise one gram water, one degree celsius = 4.18J
4.18J * 15,000g = 62,700J = 62.7kJ needed per degree C
85 - 22 = 63C temp drop needed
62.7 kJ * 63C = 3950.1kJ needed from CO2
enthalpy of CO2 = 393.51kJ/mol
CO2 = 44g/mol = 22.73 moles/kg
393.51kJ/mol * 22.73 moles/kg
= 8,943.4 kJ/kg
3950.1kJ / 8,943.4 kJ/kg = .4417 kg of CO2 needed