Answer:
126.0g of water were initially present
Explanation:
The electrolysis of water occurs as follows:
2H₂O(l) ⇄ 2H₂(g) + O₂(g)
Where 2 moles of water produce 2 moles of hydrogen and 1 mole of oxygen.
To find the mass of water we need to determine moles of oxygen and hydrogen, thus:
Moles Hydrogen:
14.0g Hâ‚‚ â‚“ (1mol / 2g Hâ‚‚) = 7 moles Hâ‚‚
Moles Oxygen:
112.0g Oâ‚‚ â‚“ (1mol / 32g) = 3.5 moles Oâ‚‚
Based on the chemical equation, the moles of water initially present were 7 moles (That produce 7 moles Hâ‚‚ and 3.5 moles Oâ‚‚). The mass of 7 moles of Hâ‚‚O is:
7 moles Hâ‚‚O * (18g / mol) =
