2Al+3H2SO4⟶3H2+Al2(SO4)3 how many moles of hydrogen will be produced from 21.9 g of aluminum?

Answer 1

From the balanced equation, determine the mole conversion factor for moles Al to moles H2. This is

3 moles H2 / 2 moles Al.

As we are given Al in grams, we need a conversion factor from grams Al to moles Al. This is obtained from the periodic table and is 26.982 grams Al = 1 mole.

As we are looking for moles of H2, write the first conversion factor with moles H2 in the numerator.

3 moles H2 / 2 moles Al.

As we are given grams of Al, we need to write the conversion factor from grams Al to moles Al,

1 mole Al / 26.952 grams Al. We want to set up this conversion factor so moles of Al will cancel the moles al in the first factor.

3 moles H2 / 2 moles Al x 1 mole Al x 26.952 g Al. Now we need to multiply these factors by the number of grams of Al given, 21.9 g.

This gives 3 moles H2 / 2 moles Al x 1 mole Al / 26.952 g Al x 21.9 g Al = 1.22 moles H2. Notice that moles Al in numerator cancels moles Al in denominator and grams Al in numerator cancels grams Al in denominator leaving only moles H2.

I hope this helps.

1 mole