Option D: 46.0 g
The balanced chemical reaction is as follows:
\(2Na+2H_{2}O\rightarrow 2NaOH+H_{2}\)
The standard temperature and pressure conditions are 273.15 K and 1 atm respectively.
First calculate the number of moles of \(H_{2}\) formed at STP,
Since, \(PV=nRT\)
Here, P is pressure, V is volume, n is number of moles, R is gas constant and T is temperature.
Rearranging the equation,
\(n=\frac{PV}{RT}=\frac{(1 atm)(22.4 L)}{(0.082 atm L K^{-1} mol^{-1})(273.15 K)}=1 mol\)
Thus, number of moles of \(H_{2}\) gas will be 1 mol.
From the chemical reaction, 2 mol of Na gives 1 mol of \(H_{2}\) thus, number of moles of Na will be 2 mol.
Molar mass of Na is 22.99 g/mol thus, mass can be calculated as follows:
\(m=n\times M=2 mol\times 22.99 g/mol=45.98 g\approx 46 g\)
Therefore, mass of Na is 46.0 g.
