An alloy of aluminum and magnesium was treated with 200.0mL sodium hydroxide solution, in which only aluminum reacts. If a sample of alloy weighing 1.400g gave 0.1352g of hydrogen, what is the percent of aluminum in the alloy? What was the molarity of the sodium hydroxide solution?
2Al(s) + 2NaOH(aq)+ 6H2O(l) à 2NaAl(OH)4(aq) + 3H2(g)