Moles, excess and limiting reagents

Find the limiting reagent in a chemical reaction with known quantities.
Consider the reaction:

2H $_2 +$ O $_2$ →2H $_2$ O
1. 50 g of O $_2$ gas and 50 g of H $_2$ gas were reacted together.
  Which reagent is the limiting reagent?
2. What mass of the other reagent is in excess?
Find the limiting reagent in a chemical reaction with known quantities.
Consider the reaction:

2C $_6$ H $_{14} +$ 19O $_2$ →12CO $_2 +$ 14H $_2$ O
1. If 120 g of O $_2$ and 150 g of C $_6$ H $_{14}$ are reacted together, what is the limiting reagent?
2. How many grams of the excess reagent are present in excess?
Find the limiting reagent in a chemical reaction with known quantities.
500 g of Fe $_2$ $_{2}$ O $_3$ $_{3}$ is reacted with 750 g of C in the reaction:

2Fe $_2$ O $_{3\;(s)} +$ 3C $_{\;(s)}$ →4Fe $_{\;(s)} +$ 3CO $_{2\;(g)}$
1. What mass of Fe is produced?
2. What is the limiting reagent in this reaction?
3. How many extra grams of this reagent are in excess?
Find the limiting reagent in a chemical reaction with known quantities.
45 g of Ca $_3$ $_{3}$ (PO $_4$ $_{4}$ ) $_2$ $_{2}$ is reacted with 36 g C and 85 g SiO $_2$ $_{2}$ according to the reaction:

2Ca $_3$ (PO $_4$ ) $_2 +$ 6SiO $_2 +$ 10C→P $_4 +$ 6CaSiO $_3 +$ 10CO
1. What mass of P $_4$ can be made from these quantities?
2. What is the limiting reagent?
3. Find the excess mass of both excess reagents.