mass of sodium required to produce 5.68 L hydrogen gas at STP from the reaction2 Na + 2 H2O ® 2 NaOH + H2?

Answer 1

We see that it takes 2 moles of Sodium to produce 1 mole of H2 gas.

How many moles of H2 are there in 5.68 Liters at STP

5.68L* 1 mole/22.4 L = 0.2536 moles round to 0.254 moles H2

We now have a ratio problem:

(x moles of Na)/(0.254 moles H2) = (2 Moles Na/1 mole H2)

solve for x, x = 0.508 mole of Sodium

We know there are 22.99 g of Na in a mole of Na

0.508 mole of Na * 22.99g/mole Na = 11.68 g of Sodium required.

Please check for errors.

Answer 2

5.68*(atomic mass of sodium)/22.4