Enough concentrated sulfuric acid solution was added to provide 3.00 grams of sulfuric acid which dissolved 4.00 grams of pure fluorapatite. How much excess sulfuric acid was used? Or, in other words how much sulfuric acid was left after it reacted.

Answer 1

Use your post above as a guide.
1. Write and balance the equation.
2. Convert grams fluorapatite to mols. mols = g/molar mass = ?
3. Use the coefficients in the balanced equation (as I did in the problem above) to convert mols fluorapatite to mols H2SO4 used.
4. Convert mols H2SO4 to grams; i.e., g = mols H2SO4 x molar mass H2SO4 = ? = g H2SO4 used.
5. Subtract g H2SO4 initially - g H2SO4 used = g H2SO4 left over.

Post your work if you get stuck.