In which of the following reactions is work done by the system to the surroundings?
A) 2CH3OH(l) + 3O2(g) --> 4H2O(l) + 2CO2(g)
B) S(s, rhombic) + O2(g) --> SO2(g)
C) 2AgNO3(s) --> 2AgNO2(s) + O2(g)
D)4Fe(s) + 3O2(g) --> 2Fe2O3(s)
My guess is B because according to w = -PΔV, the gas would be expanding in that equation and would cause work to be done on the surroundings. However, I am still a little confused and not sure if it is correct.
2 answers
I agree that it is B, however, I could most definitely be wrong.
I disagree with both of you.
A) 2CH3OH(l) + 3O2(g) --> 4H2O(l) + 2CO2(g)
3 mols gas goes to 2 mols. Not expanding so it isn't A.
B) S(s, rhombic) + O2(g) --> SO2(g)
Can't be B. 1 mols gas on left goes to 1 mol gas on the right. Volume stays the same. Not expanding.
C) 2AgNO3(s) --> 2AgNO2(s) + O2(g)
Must be C. Zero gas mols on the left to 1 mol gas on the right. Expanding. Yes, doing work on surroundings.
D)4Fe(s) + 3O2(g) --> 2Fe2O3(s)
Can't be D. 3 mols gas on left to zero on the right. Not expanding.
A) 2CH3OH(l) + 3O2(g) --> 4H2O(l) + 2CO2(g)
3 mols gas goes to 2 mols. Not expanding so it isn't A.
B) S(s, rhombic) + O2(g) --> SO2(g)
Can't be B. 1 mols gas on left goes to 1 mol gas on the right. Volume stays the same. Not expanding.
C) 2AgNO3(s) --> 2AgNO2(s) + O2(g)
Must be C. Zero gas mols on the left to 1 mol gas on the right. Expanding. Yes, doing work on surroundings.
D)4Fe(s) + 3O2(g) --> 2Fe2O3(s)
Can't be D. 3 mols gas on left to zero on the right. Not expanding.
1 answer