WorksheetsUnit 9 quick review
Total questions: 16
Worksheet time: 12mins
Entropy is always ________ in the Universe
increasing
decreasing
constant
Which has the HIGHEST entropy change?
1 --> 2 particles
gas --> liquid
solid --> gas
low to high temperature (same phase)
Which has a positive sign for S?
2Na (s) + Cl2 (g) --> 2NaCl (s)
H2O (g) --> H2O (l)
H+ (aq) + NO3- (aq) --> HNO3 (l)
CaCl2 (s) --> Ca2+ (aq) + 2Cl- (aq)
Which has a negative sign for S?
water evaporating
NaCl dissolving in water
water freezing
sublimation of CO2
reaction is ALWAYS spontaneous
- H, - S
+ H, + S
+ H, - S
- H, + S
a reaction that is exothermic and has a decrease in entropy is
spontaneous at high temps
spontaneous at low temps
always spontaneous
never spontaneous
enthalpy is driving force when
exothermic
endothermic
increase in entropy
decrease in entropy
Which of the following substances is expected to have the largest standard molar entropy?
H2O(l)
H2O(g)
H2O2(l)
H2O2(g)
The diagrams represent molecular views of the three phases of water. Information contained in the diagrams can be used to explain which of the following?
i. Why ice floats on water.
ii. Why the gas phase is more compressible than the liquid phase.
iii. Why ice melts under pressure
i only
ii only
iii only
i, ii, and iii
Which equation correctly represents the free energy change in a chemical reaction?
ΔG = ΔH + TΔS
ΔG = ΔH - TΔS
ΔG = ΔT - ΔHΔS
ΔG = ΔS - TΔH
If a process is exothermic and not spontaneous, then what MUST be true?
ΔS > 0
ΔH > 0
ΔG = 0
ΔS < 0
Which tendencies favor a spontaneous reaction?
decreasing enthalpy and decreasing entropy
decreasing enthalpy and increasing entropy
increasing enthalpy and decreasing entropy
increasing enthalpy and increasing entropy
For a reaction to be spontaneous, the Gibbs free energy must be _______
positive
neutral
negative
zero
The reaction will be ________ if the enthalpy of reaction is negative and entropy is positive
spontaneous
non spontaneous
Which of the following has a higher entropy?
carbon monoxide
carbon dioxide
