5g of magnesium is burnt in a closed vessel which contains 3g of oxygen to give magnesium oxide.

1. which is limiting reactant and why?
2. Find the mole of unreacted reactant left over.
3. How many gram of 75% pure HCl is required to react with the MgO produced in the reaction?

Ans: i. Oxygen ii. 0.020 mole iii. 18.24g

10.6g of pure Na₂CO₃ if treated with 7.9g of HCl to produce NaCl,₂O, CO₂.

1. Find the limiting reagent and calculate mole of unreacted reagent left over.
2. What volume of CO₂ gas is produced?
3. Calculate mass of NaCl formed.

Ans: (a) NaCO₃ 0.016 mol (b) 2.24 liter (c) 11.7g

3g of H₂ react 29g of O₂ to yield H₂O.

1. Which is the limiting reactant?
2. Calculate the maximum amount of H₂O that can be formed.
3. Calculate the amount of reactants which remains unreacted.

Ans: (a) H₂ is limiting reactant (b) 27g ₂O (c) 2g

2g of magnesium is burnt in a closed vessel containing 3g of oxygen.

1. which one is limiting reactant?
2. Calculate the mole of reactant left over.
3. How many gram of MgO are produced?
4. What is the mass of H₂SO₄ required to neutralize MgO formed in the reaction?

Ans: (i) Mg is limiting reagent (ii) 0.052 mol (iii) 3.33g MgO (iv) 8.15g H₂SO_4­

You are given Fe₂O₃ + 3CO => 2Fe + 3CO₂ .The reaction is carried out by mixing 130g of Fe₂O₃ and 50g of CO.

1. Calculate the limiting reactant.
2. How much mass of iron is produced?
3. How many number of moles of unreacted reactant left over?
4. Calculate the volume of CO₂ produced at 25^oC and 2 atmospheric pressure. (Given: Atomic weight of Fe = 56)

Ans: (i) CO (ii) 66.66g Fe (iii) 0.65 mol (iv) 43.54 L

A chemical reaction was carried out by mixing 25g of pure Calcium Carbonate and 0.75 mole of pure hydrochloric acid to give CaCl₂, H₂O, CO₂.

1. which one is limiting reactant?
2. Calculate the mass of CaCl₂ produced.
3. How many number of water molecules are formed?
4. what mass of NaOH is required to absorb the whole CO₂produced in the reaction?

Ans: (i) CaCO₃(ii) 27.75g (iii) 1.50 x 10²³(iv) 20g