RIO SALADO CHEM 130 EXAM SCRIPT 2026
FULL QUESTIONS AND CORRECT ANSWERS
ALREADY PASSED
◉ Reversible/irreversible . Answer: Reversible goes both directions and
will reach an equilibrium. Irreversible only goes in the forward direction
◉ Gibb's free energy . Answer: (ΔG) determines if a reaction is
spontaneous or not.
If ΔG is +, the reaction is nonspontaneous.
If ΔG is -, the reaction is spontaneous.
ΔG = sum of products - sum of reactants. can only use this when T =
25°C or 298 K.
◉ Entropy . Answer: Measure of disorder.
Everything wants to be more disordered.
g>>>>l>s: side with more moles of gas in a reaction has more entropy
of similar molecules, if all are gas, more complex molecule has more
entropy
Positive is product favored. Negative is reactant favored.
ΔS = sum of products - sum of reactants.
, ◉ Free Energy . Answer: ΔG = ΔH - TΔS (T is in K; use this when T ≠
25°C.)
Use to determine spontaneity at certain temperatures based on H and S.
Check out that chart of when H and S are positive and negative.
**don't' forget to change S to kJ!!
◉ Keq & Free Energy . Answer: ΔG = -RTlnK. R = 8.314 J/Kmol; T is
in Kelvin.
K = equilibrium constant.
K = [products]/[reactants]
◉ Redox . Answer: Redox reactions are reactions in which there is a
transfer of electrons.
For electrons: OIL RIG
For oxidation number: opposite. (ox # goes down = reduction; ox # goes
up = oxidation)
Agents are opposite too.
To find out if a reaction is a redox reaction, find the oxidation number
for each element. The oxidation numbers of 2 elements must change;
one goes up and the other goes down.
◉ Balancing . Answer: 1. Separate into half reactions
2. Balance metal
FULL QUESTIONS AND CORRECT ANSWERS
ALREADY PASSED
◉ Reversible/irreversible . Answer: Reversible goes both directions and
will reach an equilibrium. Irreversible only goes in the forward direction
◉ Gibb's free energy . Answer: (ΔG) determines if a reaction is
spontaneous or not.
If ΔG is +, the reaction is nonspontaneous.
If ΔG is -, the reaction is spontaneous.
ΔG = sum of products - sum of reactants. can only use this when T =
25°C or 298 K.
◉ Entropy . Answer: Measure of disorder.
Everything wants to be more disordered.
g>>>>l>s: side with more moles of gas in a reaction has more entropy
of similar molecules, if all are gas, more complex molecule has more
entropy
Positive is product favored. Negative is reactant favored.
ΔS = sum of products - sum of reactants.
, ◉ Free Energy . Answer: ΔG = ΔH - TΔS (T is in K; use this when T ≠
25°C.)
Use to determine spontaneity at certain temperatures based on H and S.
Check out that chart of when H and S are positive and negative.
**don't' forget to change S to kJ!!
◉ Keq & Free Energy . Answer: ΔG = -RTlnK. R = 8.314 J/Kmol; T is
in Kelvin.
K = equilibrium constant.
K = [products]/[reactants]
◉ Redox . Answer: Redox reactions are reactions in which there is a
transfer of electrons.
For electrons: OIL RIG
For oxidation number: opposite. (ox # goes down = reduction; ox # goes
up = oxidation)
Agents are opposite too.
To find out if a reaction is a redox reaction, find the oxidation number
for each element. The oxidation numbers of 2 elements must change;
one goes up and the other goes down.
◉ Balancing . Answer: 1. Separate into half reactions
2. Balance metal
