A 0.250-g sample of a magnesium-aluminum alloy dissolves completely in an excess of HCl (aq) . When the liberated H2 (g) is collected over water at 29 degrees celsius and 752 torr, the volume is found to be 301 mL . The vapor pressure of water at 29 degrees celsius is 30.0 torr.

Part A
How many moles H2 of can be produced from x grams of Mg in magnesium-aluminum alloy? The molar mass of Mg is 24.31 g/mol .

Part B
How many moles of H2 can be produced from y grams of Al in magnesium-aluminum alloy? The molar mass of Al is 26.98 g/mol.

8 answers

I think there is a lot of extraneous material in the problem. That may be confusing you.
A. Mg + 2HCl ==> MgCl2 + H2
moles Mg = x/24.32.

Using the coefficients in the balanced equation, convert moles Mg to moles H2
(x/24.32) x (1 mole H2/1 mol Mg)

Now convert moles H2 to grams H.
(x/24.32) x (1 molH2/1 molMg) x (2 g H/1 mol H2) = ??

B is done the same way but the numbers will be different since it is a different equation.
I'll let you finish.
48.62x
Really? This is your equation for part A? **Please do not use this or it will be wrong..
Works for me
How many moles of H2 can be produced from x grams of Mg in magnesium-aluminum alloy? The molar mass of Mg is 24.31 g/mol.
x g Mg×1 mol Mg/24.3050 g Mg×1 mol H2/1 mol Mg=0.0411x mol H2
0.0411x mol H2
How many moles of H2 can be produced from y grams of Al in magnesium-aluminum alloy? The molar mass of Al is 26.98 g/mol.
y g Al×1 mol Al/26.982 g Al×3 mol H2/2 mol Al=0.0556y mol H2
0.0556y mol H2
hm ok anyways
Rachel is right
thank u rachel