The purpose is that it shows you all the elements we know and it arranges them in groups that are also the same kind like Chemistry.
<span>570 torr.
The ideal gas law is
PV = nRT
where
P = pressure
V = volume
n = number of moles of gas particles
R = Ideal gas constant
T = absolute temperature
Since the value n, R, and T remain constant for this problem, that indicates that if the volume is doubled, the pressure will be halved. So the new pressure will be 1.50 atm / 2 = 0.750 atm. Now we just need to convert that from atm to torr. 1 atm is equal to 760 torr, so 0.750 atm * 760 torr/atm = 570 torr.</span>
The answer is the third choice because is oxidation half reactions, only the oxidation state of the reducing agent changes; in this third choice, Fe2+ is oxidized and becomes Fe3+. Just keep in mind that half reactions usually include the change in electrons:
Fe2+ -> Fe3+ +e-<span />
