Gen Chem 1

Stoichiometry practice with use of Concentration

This section uses the reactions from above. The reactions are provided unbalanced here. Get in the habit of always checking to see if a reaction is balanced before proceeding with the problem.

Ca(OH)₂ +Na₂CO₃ →CaCO₃ + NaCl

15.0mL of a 0.884M Ca(OH)­₂ solution reacts with excess Na­₂CO₃. How many grams of CaCO₃ will be produced?

KMnO₄ + HCl → KCl + MnCl₂ + H₂O + Cl₂

44.1g KMnO₄ reacts in an excess of HCl. How many grams of Cl­₂ is produced?

How many mL of a 15.8 M solution would be needed to prepare 30.0 L of a 1.60 M solution of HNO₃?

Limiting Reagents

Using the information provided below, determine the limiting reagent, theoretical yield, and percent yield, where applicable. Remember to balance the chemical reaction first.

1. How many grams of NH₃ can be produced from the reaction of 28 g of N₂ and 25 g of H₂? N₂ + H₂ → NH₃

2. How many grams of water can be formed from the reaction of 3.75 g of NH₃ with 3.50 g of O₂? NH₃ (aq) + O₂ (g) → NO (g) + H₂O (l)

3. 22.0 g of sodium nitrate reacts with 16.0 g of sulfuric acid (H₂SO₄). Which of these will be the EXCESS reactant? What mass of that excess reactant will be left over once they have reacted together?

4. If 14.0 g of aluminum hydroxide reacts with 120. mL of 2.50M HCl, and 12.0 g of aluminum chloride is produced, what is the percent yield? Al(OH)₃ (s) + HCl (aq) → AlCl₃ (aq) + H₂O (l)

5. What is the percent yield if 27.1 g of NH₃ are produced from 77.0 g of calcium cyanide? Ca(CN)₂ (aq) + H₂O (l) → C(s) + CaCO₃ (s) + NH₃ (aq)