What volume of chlorine gas at 42.0◦C and 1.64 atm is needed to react completely with 10.8 g of sodium to form NaCl?
Units of L.
2 Na + Cl2 --> 2NaCl
mols Na = g/atomic mass = 10.8/23 = about 0.47 but you need to redo this and all other calculations.
Convert mols Na to mols Cl2 needed using the coefficients in the balanced equation.
0.47 moles Na x (1 mol Cl2/2 mols Na) = 0.47 x 1/2 = about 0.23. Again redo.
Then use PV = nRT as in the first problem and solve for volume. Post your work if you get stuck.