Given that 12.25 g of aluminum sulfide is reacted with excess water. How many grams of aluminum hydroxide can be obtained? The molar mass of aluminum sulfide is 150.0 g and the molar mass of aluminum hydroxide is 78.0 g.

Answer 1

Al2S3 + 6H2O ==> 2Al(OH)3 + 3H2S

mols Al2S3 = grams/molar mass = ?
Use the coefficients in the balanced equation to convert mols Al2S3 to mols Al(OH)3.
now convert mols Al(OH)3 to grams Al(OH)3. That's g = mols x molar mass = ?

Answer 2

How many grams of HF will be made if you start with 29.6 grams of ammonia and fluorine is in excess?