For the reaction #2Na + 2H_2O -> NaOH + H_2#, how many grams of hydrogen are produced from 130 g of sodium?

1 Answer
May 25, 2017

Answer:

Well how many moles of sodium metal do you have......?

Explanation:

#"Moles of sodium"=(130*g)/(22.99*g*mol^-1)=5.65*mol.#

Now you have the stoichiometric equation:

#2Na(s) + 2H_2O(l) rarr 2NaOH(aq) + H_2(g)uarr#

If there are #5.65*mol# of metal, clearly #(5.65*mol)/2# dihydrogen gas are evolved......, i.e. #2.83*mol# #H_2#. Typically, in a question like this, you would also be asked to calculate the volume the gas occupies under standard conditions, and the #pH# of the resultant solution (would it be high, low, neutral?).

Just as an aside, I would not want to be the mug who placed such a quantity of sodium metal in water. The reaction would be violent and explosive.