Share
Explore BrainMass

Chemistry Change Questions

1- Determine the sign of ΔS sys and ΔS surr for each chemical reaction.2CO(g)+O 2 (g)⇌2CO 2 (g)ΔH ∘ rxn = -566.0 kJ. Choose from:

ΔS sys >0 , ΔS surr >0
ΔS sys <0 , ΔS surr >0
ΔS sys >0 , ΔS surr <0
ΔS sys <0 , ΔS surr <0

2-Determine the sign of ΔS sys and ΔS surr for each chemical reaction.2NO 2 (g)→2NO(g)+O 2 (g)ΔH ∘ rxn = +113.1 kJ. Choose from:

ΔS sys >0 , ΔS surr >0
ΔS sys <0 , ΔS surr >0
ΔS sys >0 , ΔS surr <0
ΔS sys <0 , ΔS surr <0

3-Determine the sign of ΔS sys and ΔS surr for each chemical reaction.2H 2 (g)+O 2 (g)→2H 2 O(g)ΔH ∘ rxn = -483.6 kJ . choose from:

ΔS sys >0 , ΔS surr >0
ΔS sys <0 , ΔS surr >0
ΔS sys >0 , ΔS surr <0
ΔS sys <0 , ΔS surr <0

4-Determine the sign of ΔS sys and ΔS surr for each chemical reaction.CO 2 (g)→C(s)+O 2 (g)ΔH ∘ rxn = +393.5 kJ . Choose from:
ΔS sys >0 , ΔS surr >0
ΔS sys <0 , ΔS surr >0
ΔS sys >0 , ΔS surr <0
ΔS sys <0 , ΔS surr <0

5-In photosynthesis, plants form glucose (C 6 H 12 O 6 ) and oxygen from carbon dioxide and water.Calculate ΔH ∘ rxn at 15 ∘ C and Calculate ΔG ∘ rxn at 15 ∘ C .

Solution Preview

1. Determine the sign of ΔS sys and ΔS surr for each chemical reaction.2CO(g)+O 2 (g)⇌2CO 2 (g)ΔH ∘ rxn = -566.0 kJ.

ΔS sys <0 , ΔS surr >0

If we have an exothermic reactions with a constant temperature, the system would cause heat to flow into the surroundings, which causes ΔS surr to become positive. So, ΔS surr >0.

Since 3 molecules (2 molecules of CO and a molecule of O2) of gases combine to give 2 molecules of CO2, the freedom is lost ...

Solution Summary

The expert determines the sign for entropy. Reactions for chemicals are provided.

$2.19