*I apologize that you can't see what I wrote on the board*

"If 1.00 gram of aluminum hydroxide reacts with 3.00 grams of sulfuric acid, what is the mass of water produced?"

The balanced equation for this reaction is:
2Al(OH)3(s) + 3H2SO4 produces Al2(SO4)3 + 6 H2O.

We must determine which reactant 1.00g Al(OH)3 or 3.00g H2SO4 is the limiting reactant (AKA which reactant will produce the least mass of H20).
First, we must calculate the mass of H2O that can be produced be 1.00g Al(OH)3. To do this we mus calculate how many moles are in 1.00g Al(OH)3 using the molar mass of Al(OH)3:
1.00g Al(OH)3 x 1 mole Al(OH)3/78.004g Al OH3=0.0128 moles Al(OH)3. Next we apply the mole to mole ratio to convert moles of Al(OH)3 to moles H2O using the coefficients from the balanced equation: 0.0128 mole Al(OH)3 x 6 moles H2O/2moles Al(OH)3= 0.0385 moles H2O. Finally, we determine the mass of the H2O by multiplying it's molar mass by the number of moles of H2O: 0.0385 mol H2O x 18.016g H2O/1mol H2O = .693g H2O of product.

Part 2: We must Calculate the mass of H2O that can be produced from 3.00g H2SO4. (a) Calculate the moles of the reactant. (b) Calculate the moles of the product. (c) Calculate the mass of the product. Now let's convert the given mass of 3.00 grams of H2SO4 to number of moles by dividing 3g H2SO4 by the molar mass of H2SO4: 3.00g H2SO4 x Imole H2SO4/98.086g H2SO4 = 0.03059 mol H2SO4. Next, we apply the mole ratio to convert the moles of the H2SO4 to the moles of H2O using the coefficients from the balanced equation" 0.03059 mol H2SO4 * 6 mol H2O/3 mol H2SO4 = 0.06118 mol H2O. Finally, we determine the mass of the H2O by multiplying it's molar mass by number of mol H2O: 0.06118 mol H20 * 18.016g H2O= 1.102g H2O product.

So, 1.00g AL(OH)3 produced 0.693g H2O and 3.00g H2SO4 produced 1.102g H2O. Because Al(OH)3 produced the least amount of H2O (and will be totally consumed when this chemical reaction is complete) it determines how much H2O is produced. The limiting reactant gives the least amount of product. The actual mass of product obtained from the chemical reaction is the lesser of the 2 product masses, therefore the limiting reactant is Al(HO)3 and the mass of H2O produced in this chemical reaction is 0.693g H2O. Thanks for watching!