In which of the following reactions does the system perform work on the environment? 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 expand in this equation and cause work to be done on the surroundings. However, I’m still a bit confused and not sure if this is correct. I disagree with you two.
A) 2CH3OH(l) + 3O2(g) –> 4H2O(l) + 2CO2(g)
3 mol of gas goes to 2 mol. No expansion so it’s not A.
B) S(s, rhombic) + O2(g) –> SO2(g)
Cannot be B. 1 mol of gas on the left goes to 1 mol of gas on the right. The volume remains the same. Not expanding.
C) 2AgNO3(s) –> 2AgNO2(s) + O2(g)
Must be C. Zero mol of gas on the left to 1 mol of gas on the right. Expansion. Yes, doing environmental work.
D)4Fe(s) + 3O2(g) –> 2Fe2O3(s)
Cannot be D. 3 mol gas left to zero right. Not expanding.
I agree it’s B, however, I could most definitely be wrong.