How many molecules of hydrogen gas are formed when 24.6 g of sodium are added to water. Please show work.

2Na + 2H2O ==> H2 + 2NaOH

mols Na = grams/atomic mass = ?
Using the balanced equation, convert mols Na to mols H2. The equation tells you mols H2 is 1/2 mols Na.
So now you know mols H2 and you know each mol H2
gas contains 6.02E23 individual molecules.
Post your work if you get stuck.