AP Chemistry: Thermodynamics & Thermochemistry 2

Question 1

What is the sign of ΔH for an endothermic reaction?

Accepted Answer

Positive

Answer

Negative

Answer

Zero

Answer

Always equal to ΔS

Question 2

A 50.0 g sample of water (c = 4.18 J/g·°C) is heated from 20.0 °C to 30.0 °C. How much heat is absorbed?

Accepted Answer

2090 J

Answer

209 J

Answer

418 J

Answer

1045 J

Question 3

Which quantity is a state function?

Accepted Answer

Enthalpy

Answer

Heat

Answer

Work

Answer

Both heat and work

Question 4

According to Hess's law, the enthalpy change of a reaction depends on what?

Accepted Answer

Only the initial and final states

Answer

The number of steps taken

Answer

The reaction rate

Answer

The catalyst used

Question 5

What does a negative ΔG indicate about a process?

Accepted Answer

It is spontaneous

Answer

It is nonspontaneous

Answer

It is at equilibrium

Answer

It absorbs heat

Question 6

In the equation ΔG = ΔH − TΔS, what does T represent?

Accepted Answer

Absolute temperature in kelvin

Answer

Temperature in Celsius

Answer

Time

Answer

Heat capacity

Question 7

What is the standard enthalpy of formation of an element in its standard state?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Equal to its molar mass