True, all matter has mass and takes up space.
m = 7.84x107/(3x108)2kg = 7.84x107/9x1016kg = 0.871x10-9 kg = 8.71x10-10 kg
The half-reaction are:
Cd ---> Cd(OH)₂
The oxidation number of Cd changed from 0 to +2. So, the number of mol electron transferred here is 2.
NiO(OH) --> Ni(OH)₂
The oxidation number of Cd changed from +3 to +2. So, the number of mol electron transferred here is 1.
Now, the greatest common factor would be 2. So, we use n=2 for the formula for ΔG°. F is Faraday's constant equal to 96,485 J/mol e.
ΔG° = nFE° = (2)(96,485)(1.5) =<em> 289,455 J</em>
the mass of 1 mole of phosphorus atoms is approximately 30
g
hope this helps :)