Sodium metal reacts violently with water to form NaOH and release hydrogen gas. Suppose that 3.00 g of Na reacts completely with 3.00 L of water and the final volume of the system is 3 L. What is the molarity M of the NaOH Solution formed by the reaction?

1 answer

2Na + 2H2O ==> H2 + 2NaOH
mols Na = 3/23 = estimated 0.13

mols NaOH formed = 0.13mols Na x (2 mols NaOH/2 mol Na) = 0.13 x 2/2 = 0.13 mols NaOH.
M NaOH = mols NaOH/L H2O
Substitute and solve for M.