Please help me. I have worked on this for 2 days. I don't understand the ratio of this equation.4Na+O2 to 2Na2O.

for question: How many grams of Na2O are produced when 81.ograms of Na reacts?

2 answers

A four step procedure will work these problems.

1. Write and balance the equation.
You have that.

2. Convert what you have (in this case 81.0 g Na) to mols. mol = grams/molar mass = ?

3. Using the coefficients in the balanced equation, convert mols of what you have (Na) to mols of what you want (in this case Na2O).
?mols Na x (2 mols Na2O/4 mols Na) = ? mols Na x (2/4) = ? mols Na x 1/2 = ?

4. Now convert mols of what you want (Na2O) to grams. g = mols x molar mass
How many moles of aluminum ions are present in 0.50 mole of Al2(SO4)3?