Answer:
C
Explanation:
A fuel cell uses both hydrogen and oxygen as fuels. At the cathode oxygen is reduced to water according to the equation
O2+4H^+ +4e ------>2H2O
And hydrogen is oxidized at the anode:
2H2------>4H^+ +4e
Fuel cells produce only water as a by product hence they are environment friendly
207 is the mass number. 82 would be the atomic number
First, find how many grams are in 1 mole of water.
For a hydrogen atom, there is about 1 gram per mole. For an oxygen atom, there are about 16 grams per mole.
In H2O, there are two hydrogen atoms and one oxygen atom. This means there are 18 grams in one mole of water. Multiply the mass in one mole by your number of moles.
18 x 11.8 = 212.4 grams
You have 212.4 grams of water.