Solution Stoichiometry: A Step-by-Step Guide with Examples

📚 Quick Study Guide

• ⚗️ Solution stoichiometry involves using molarity and volume to determine the amounts of reactants and products in reactions that occur in solution.
• 🧮 Molarity ($M$) is defined as moles of solute per liter of solution: $M = \frac{\text{moles of solute}}{\text{liters of solution}}$.
• ⚖️ Balanced chemical equations are essential for determining mole ratios between reactants and products.
• 🌡️ Always ensure units are consistent (e.g., convert mL to L) before calculations.
• 🧪 Titration is a common technique used in solution stoichiometry to determine the concentration of an unknown solution.
• 💡 Key steps: (1) Balance the equation, (2) Convert to moles, (3) Use the mole ratio, (4) Convert to desired units.
• 📝 Remember: $n = MV$, where $n$ is moles, $M$ is molarity, and $V$ is volume in liters.

🧪 Practice Quiz

1. What volume of 0.200 M NaCl solution is needed to react completely with 0.100 mol of $AgNO_3$ in the reaction $AgNO_3(aq) + NaCl(aq) \rightarrow AgCl(s) + NaNO_3(aq)$?
   1. 0.200 L
   2. 0.500 L
   3. 1.00 L
   4. 2.00 L
2. If 25.0 mL of a 0.100 M $H_2SO_4$ solution is required to neutralize 20.0 mL of a NaOH solution, what is the molarity of the NaOH solution?
   1. 0.125 M
   2. 0.250 M
   3. 0.080 M
   4. 0.0625 M
3. How many grams of $BaSO_4$ will be formed when 100.0 mL of 0.500 M $BaCl_2$ reacts with excess $Na_2SO_4$ according to the equation $BaCl_2(aq) + Na_2SO_4(aq) \rightarrow BaSO_4(s) + 2NaCl(aq)$? (Molar mass of $BaSO_4$ = 233.39 g/mol)
   1. 11.7 g
   2. 23.3 g
   3. 5.83 g
   4. 1.17 g
4. What is the molarity of a solution prepared by dissolving 10.0 g of $CuSO_4 \cdot 5H_2O$ (Molar mass = 249.68 g/mol) in enough water to make 500.0 mL of solution?
   1. 0.0801 M
   2. 0.100 M
   3. 0.200 M
   4. 0.0400 M
5. In the reaction $2HCl(aq) + Ba(OH)_2(aq) \rightarrow BaCl_2(aq) + 2H_2O(l)$, what volume of 0.150 M $HCl$ is required to neutralize 25.0 mL of 0.100 M $Ba(OH)_2$?
   1. 16.7 mL
   2. 33.3 mL
   3. 8.33 mL
   4. 50.0 mL
6. If 30.0 mL of 0.200 M $AgNO_3$ is mixed with 20.0 mL of 0.300 M $NaCl$, what is the concentration of $Ag^+$ ions remaining in solution after the reaction $AgNO_3(aq) + NaCl(aq) \rightarrow AgCl(s) + NaNO_3(aq)$ goes to completion?
   1. 0.00 M
   2. 0.020 M
   3. 0.060 M
   4. 0.120 M
7. What mass of $KCl$ is needed to prepare 250.0 mL of a 0.400 M solution? (Molar mass of $KCl$ = 74.55 g/mol)
   1. 3.73 g
   2. 7.46 g
   3. 14.9 g
   4. 37.3 g