Thermochemistry

Define work.

• the flow of energy caused by a chemical reaction

• the flow of energy caused by a temperature difference

• the result of a force acting through a distance

• the capacity to do work

Which of the following signs on q and w represent a system that is doing work on the surroundings, as well as losing heat to the surroundings?

• q = +, w = +

• q = +, w = -

• q = -, w = +

• q = -, w = -

Which of the following signs on q and w represent a system that is doing work on the surroundings, as well as gaining heat from the surroundings?

• q = -, w = -

• q = +, w = -

• q = +, w = +

• q = -, w = +

Calculate the change in internal energy (ΔE) for a system that is giving off 60.0 kJ of heat and is performing 855 J of work on the surroundings.

• 60.0 x 10^2 kJ

• -60.9 kJ

• -59.1 kJ

• 59.1 kJ

If energy flows into a chemical system and out of the surroundings, what is the sign of ΔEsystem?

• ΔEsystem < 0

• ΔEsystem = 0

• ΔEsystem > 0

If the internal energy of the products of a reaction is higher than the internal energy of the reactants, what is the sign of ΔE for the reaction?

• ΔE < 0

• ΔE = 0

• ΔE > 0

In which direction does energy flow?

• into the system from the surroundings

• from the system into the surroundings

Heat capacity is ______.

• the quantity of heat required to change a system's temperature by 1°C

• the quantity of heat required to lower the temperature of 1 mole of a substance by 1°C

• the quantity of heat required to raise the temperature of 1 gram of a substance by 1°F

• the quantity of heat required to raise the temperature of 1 liter of a substance by 1°F

• the quantity of heat required to raise the temperature of 1 gram of a substance by 1°C

What is specific heat capacity?

• The quantity of heat required to raise the temperature of 1 gram of a substance by 1°C

• The quantity of heat required to lower the temperature of a substance by 1°F

• The quantity of heat required to raise the temperature of 1 mole of a substance by 1°F

• The quantity of heat required to change a system's temperature by 1°C

• the quantity of heat required to lower the temperature of 1 liter of a substance by 1°F

In the formula q=mCΔT, what does 'm' represent?

• Mass (g)

• Molarity (M)

• Meters (m)

• Moles (mol)