Thermochemistry: Objective type question in Thermochemistry

Find the correct answer by clicking on the choice given. 1. A 100 g sample of water at 25 oC and 1 atm. of pressure _?_ than 100 g of water that has recently been heated to 100 oC from 0 oC and then cooled to 25 oC at 1 atm. of pressure.
	(a)	has more internal energy than
	(b)	has less internal energy than
	(c)	has the same internal energy as
2. If a system loses 250 kJ of heat at the same time that it is doing 500 kJ of work, what is the change in the internal energy of the system?
	(a)	+250 kJ
	(b)	-250 kJ
	(c)	+750 kJ
	(d)	-750 kJ
3. If 1.45 J of heat are added to a 2.00 g sample of aluminum metal and the temperature of the metal increases by 0.798 oC, what is the specific heat of aluminum?
	(a)	0.579 J/g deg
	(b)	0.909 J/g deg
	(c)	1.68 J/g deg
	(d)	3.63 J/g deg
4. Water has a specific heat of 4.184 J/g deg while glass (Pyrex) has a specific heat of 0.780 J/g deg. If 10.0 J of heat is added to 1.00 g of each of these, which will experience the larger increase of temperature?
	(a)	glass
	(b)	water
	(c)	They both will experience the same change in temperature since only the amount of a substance relates to the increase in temperature.
5. How many PopTarts® are needed to convert 1,000.0 g of water at 20.0 oC to steam at 100.0 oC? One PopTart is equal to 800,000 J of energy...wow!
	(a)	0.419 PopTart
	(b)	2.83 PopTarts
	(c)	3.25 PopTarts
6. The heat of combustion for 1 mole of carbon to carbon dioxide is -410 kJ. How many kJ of heat would be liberated from the complete combustion of 60.0 g of carbon?
	(a)	-82 kJ
	(b)	-2050 kJ
	(c)	-24,600 kJ
7. Given the following data at 1 atm of pressure and 25.0 oC... DHoformation = +64.4 kJ/mole for Cu2+ DHoformation = -152.4 kJ/mole for Zn2+ DHoformation = 0 for both Zn and Cu because these are in the most stable state. Calculate the standard heat of reaction for...
	(a)	-217 kJ/mole
	(b)	+217 kJ/mole
	(c)	-88.0 kJ/mole
	(d)	+88.0 kJ/mole
8. A 1.00 g sample of NH4NO3 is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K. The heat capacity of the system is 1.23 kJ/g·deg. What is the molar heat of decomposition for ammonium nitrate?
	(a)	-7.53 kJ/mole
	(b)	-16.1 kJ/mole
	(c)	-398 kJ/mole
	(d)	-602 kJ/mole
9. A sample of 10.6 g of KNO3 was dissolved in 251.0 g of water at 25 oC in a calorimeter. The final temperature of the solution was 21.5 oC. What is the molar heat of solution of KNO3? Assume the Csp of the solution is 4.184 J/gdeg and that the calorimeter does not gain or lose heat.
	(a)	+3830 J/mole
	(b)	-3830 J/mole
	(c)	+36,500 J/mole
	(d)	-36,500 J/mole
10. What is the molar enthalpy of reaction for the combustion of methane? The balanced chemical equation and the bond energies for the various bonds in the reactants and products are...
	(a)	+80 kJ/mole
	(b)	-284 kJ/mole
	(c)	+668 kJ/mole
	(d)	-668 kJ/mole