Solid sodium reacts violently with water, producing heat, hydrogen gas, and sodium hydroxide. How many liters of hydrogen gas are formed when 4g of sodium are added to water ?
Na + 2H O 2NaOH + H
The correct balanced equation is and I assume you want the volume of H2 @ STP.
2Na + 2H2O ==> 2NaOH + H2
mols Na = g/atomic mass = 4/40 = 0.1
The coefficients tell you that 0.1 mol Na will produce 1/2 x 0.1 = 0.05 mols H2 gas.
1 mol of the gas occupies a volume of 22.4 L @ STP so
0.05 mol x 22.4 L/mol = ?