1. Balanced Chemical Equation:

The electrolysis of water produces hydrogen and oxygen gas:

2 H₂O(l) → 2 H₂(g) + O₂(g)

2. Moles of Water:

* Calculate the moles of water using its molar mass (18.015 g/mol):

Moles of H₂O = (90 g) / (18.015 g/mol) = 5 moles

3. Moles of Hydrogen:

* From the balanced equation, 2 moles of water produce 2 moles of hydrogen. Therefore, 5 moles of water produce 5 moles of hydrogen.

4. Volume of Hydrogen at STP:

* At STP (Standard Temperature and Pressure: 0°C and 1 atm), 1 mole of any gas occupies 22.4 liters.

* Calculate the volume of hydrogen:

Volume of H₂ = (5 moles) * (22.4 L/mol) = 112 L

Answer: 112 liters of hydrogen gas would be produced at STP.