If 0.790 mol of solid TiO2 and 8.53 g of solid C are reacted stoichiometrically according to the balanced equation, how many moles of solid TiO2 remain?

Question

3TiO2(s) + 4C(s) + 6Cl2(g) → 3TiCl4(l) + 2CO2(g) + 2CO(g)

Answer 1

Change C to moles.
8.53 g/12.01 = ?? mols
Now convert moles TiO2 to moles of any one of the products, say TiCl4.
Convert moles C to moles TiCl4.
That will give you the limiting reagent; either TiO2 or C.
Using the limiting reagent (which I assume will be C), convert moles C to moles TiO2 and subtract from the initial moles of TiO2 to find the amount of TiO2 remaining after reaction.