Need a Balanced Chemical Equation-Sodium Hydroxide + Aluminum?

Question

I'm doing a chemistry assignment for school and need to make hydrogen gas efficiently so i can fill up a balloon to lift a 5g weight. Im thinking either electrolysis, Mg +2HCl -> MgCl2 + H2 or i could just mix Sodium Hydroxide with Aluminum to give me H2 gas but i can't figure out what the equation is and what reacts with each other because Al And Na are both cations and do not react with each other. Can someone please shed some light on my situation?

Answer 1

Perhaps you should stick with reacting a metal with an acid, since:

acid + metal --> salt + hydrogen

The reaction you gave is a good one, if a little exothermic:

Mg + 2HCl --> MgCl2 + H2

Perhaps swop out Magnesium for some Iron filings.

Answer 2

3 NaOH + Al -> no reaction. Sodium is more reactive than Al so it will not be displaced by the Al. Reacrivity series of metals dictate that metals of higher reactivity cannot be displaced by metals of lower reactivity in a reaction.

Go for Mg + 2HCl -> Mg(Cl)2 + H2

Its guaranteed to work due to the displacement of Mg with the H+ of the HCl.

Answer 3

2 Al(s) + 6 NaOH(aq) --> 3 H2 (g) + 2 Na3AlO3(aq)

The Al reacts with the excess O to form AlO3(3-), which then reacts with the sodium to give the 2 Na3AlO3(aq), and the leftover hydrogen.

Hope that helps.