How many grams MgCl2 will be formed from 25.6 mL of a 0.100M HCl solution reacting with excess magnesium metal

Answer 1

the solution contains

.0256L * .100mol/L = .00256 mol

Mg + 2HCl = MgCl2 + H2

each 2 moles of HCl produces 1 mole of MgCl2

So, you get .00128 moles of MgCl2
or, .00128 * 59.76 = 0.076g of MgCl2