Aluminum granules are a component of some drain cleaners because they react with sodium hydroxide to release both energy and gas bubbles to help clear the drain clog. The reaction is:

Question

Aluminum granules are a component of some drain cleaners because they react with sodium hydroxide to release both energy and gas bubbles to help clear the drain clog.  The reaction is:

2NaOH  +  Al  +  6H2O    2NaAl(OH)4  +  3H2
(note: balance the reaction first)

What mass of Aluminum would be needed to produce 4L of hydrogen gas at STP?

DrBob222 · Answer

2NaOH + 2Al + 6H2O  2NaAl(OH)4 + 3H2

Use PV = nRT and solve for n = mols H2 OR remember at STP 1 mol occupies 22.4L.

Using the coefficients in the balanced equation, convert mols H2 to mols Al
Then mols Al = grams/atomic mass. You know atomic mass and mols, solve for grms.