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1) Constant-volume calorimeters are sometimes calibrated byrunning a combustion reaction of known ΔE and measuring the changein temperature. For example, the combustion energy of glucose is15.57 kJ/g. When a 2.500 g sample of glucose burns in a constantvolume calorimeter, the calorimeter temperature increases from21.45 to 23.34°C. Find the total heat capacity of the calorimeter(in kJ/K).

2)An electrical heater is used to add 18.25 kJ of heat to aconstant-volume calorimeter. The temperature of the calorimeterincreases by 3.40°C. When 2.25 g of ethanol(C₂H₅OH) is burned in the same calorimeter,the temperature increases by 12.45°C. Calculate the molar heat ofcombustion for ethanol (enter in kJ).

3)A 0.90 g sample of caffeine,C₈H₁₀N₄O₂, burns in aconstant-volume calorimeter that has a heat capacity of 7.85 kJ/K.The temperature increases from 298.25 K to 303.34 K. What is themolar heat of combustion of caffeine (in kJ).

4)Use standard enthalpies of formation to determineΔH^o_rxnfor:

2Al(s) + 3Cl₂(g) → 2AlCl₃(s)  Find the change in internal energy for this reaction.Enter in kJ.

5)Use standard enthalpies of formation to determineΔH^o_rxn for:

2NH₃(g) + 3O₂(g) + 2CH₄(g) →2HCN(g) + 6H₂O(g) Find the change in internal energy forthis reaction. Enter in kJ.