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Determing concentrations of solutions

Determing concentrations of solutions. MOLAr. Molar is mol solube /1 L solution Making molar solution Add ½ of the total solvent Add required amount of solute Add water until final volume of solution. Make 2 L of 3 M sodium chloride. Determine how much NaCl is needed

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Determing concentrations of solutions

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  1. Determing concentrations of solutions

  2. MOLAr Molar is molsolube/1 L solution Making molar solution • Add ½ of the total solvent • Add required amount of solute • Add water until final volume of solution

  3. Make 2 L of 3 M sodium chloride Determine how much NaCl is needed (3 molNaCl/1 L solution) * 2 L solution = 6 molNaCl (6 molNaCl) * (58.44 g NaCl/1 molNaCl) = 350.64 g NaCl Mix solution • Add 1 L water to beaker or flask • Add 350.64 g NaCl and stir until dissolved • Add water until there is exactly 2 L of solution

  4. Make 1.7 L of 2 M sodium chloride Determine how much NaCl is needed (2 molNaCl/1 L solution) * 1.7 L solution = 3.4 molNaCl (3.4 molNaCl) * (58.44 g NaCl/1 molNaCl) = 198.70 g NaCl Mix solution • Add .9 L water to beaker or flask • Add 198.70 g NaCl and stir until dissolved • Add water until there is exactly 1.7 L of solution

  5. Determining the concentration Molar is mol solute/L solution Determine concentration • Determine how many moles of solute • Divide by total liters of solution

  6. What is the concentration? What is the concentration if 43.12 g NaCl is dissolved in 2.2 L of solution? • Determine moles of NaCl 43.12 g NaCl (1 molNaCl/58.44 g NaCl) = .74 molNaCl 2) Divide moles by volume .74 molNaCl/2.2 L solution = .34 M NaCl

  7. What is the concentration? What is the concentration if 97.63 g NaCl is dissolved in 2.7 L of solution? • Determine moles of NaCl 97.63 g NaCl (1 molNaCl/58.44 g NaCl) = 1.67 molNaCl 2) Divide moles by volume 1.67 molNaCl/2.7 L solution = .62 M NaCl

  8. How many grams? • How much NaCl is in 2 L of 4 M NaCl? • It’s all dimensional analysis • (4 mol NaCl/1 L solution)(2 L solution)(58.44 g NaCl/1 mol NaCl) = 467.52 g NaCl

  9. How many grams? • How much NaCl is in 617 mL of 3.5 M NaCl? • (3.5 mol NaCl/1 L solution)(617 mL solution)(1 L solution/1000 mL solution)(58.44 g NaCl/1 mol NaCl) = 467.52 g NaCl

  10. How many grams? • How much NaCl is in 617 mL of 3.5 M NaCl? • (3.5 mol NaCl/1 L solution)(617 mL solution)(1 L solution/1000 mL solution)(58.44 g NaCl/1 mol NaCl) = 467.52 g NaCl

  11. Diluting a solution • Adding water to a solution dilutes it, reducing the concentration • A new concentration of a diluted solution is found using the following formula • C1V1 = C2V2 • C1 = original concentration • V1 = amount of original solution • C2 = new concentration • V2 = new volume (original solution volume + volume of water added)

  12. What is the new concentration if 10 mL of 4M NaCl is combined with 40 mL of water? • C1V1 = C2V2 • (4M)(10 mL) = C2(50 mL) • C2 = .8M NaCl

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