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S olubility & C oncentration. CREDIT: D. Scott, CHS. Concentration of Solution. Solvent Solute. Molarity Parts ratio Mole Fraction. Concentration of Solution. Moles of solute. Mol. L. Liter of solution. amount of solute (g or ml). amount of solution (g or ml).
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Solubility&Concentration CREDIT: D. Scott, CHS
Concentration of Solution Solvent Solute
Molarity Parts ratio Mole Fraction Concentration of Solution Moles of solute Mol L Liter of solution amount of solute (g or ml) amount of solution (g or ml) Moles of solute Total moles of solution (M) = = = (102) or (106) or (109) (c) =
Molarity MolarityExample Problem 1 NaCl 12.6 g of NaCl are dissolved in water making 344mL of solution. Calculate the molar concentration.
Molarity MolarityExample Problem 2 NaCl How many moles of NaCl are contained in 250.mL of solution with a concentration of 1.25 M? Volume x concentration = moles solute
Molarity MolarityExample Problem 3 NaCl What volume of solution will contain 15 g of NaCl if the solution concentration is 0.75 M? moles solute ÷ concentration = volume solution
% Concentration • % (w/w) = • % (w/v) = • % (v/v) = Mass and volume units must match. (g & mL) or (Kg & L)
% Concentration (Solid in a Liquid) What is the concentration in %w/v of a solution containing 39.2 g of potassium nitrate in 177 mL of solution? Example Problem 1 % (w/v) = Example Problem 2 (Liquid in a Liquid) What is the concentration in %v/v of a solution containing 3.2 L of ethanol in 6.5 L of solution? % (v/v) =
% Concentration What volume of 1.85 %w/v solution is needed to provide 5.7 g of solute? Example Problem 3 % (w/v) = We know: We want to get: g solute ÷ concentration = volume solution
ppm = ppb = Parts per million/billion (ppm & ppb) AND For very low concentrations: = ppt parts per trillion or = ppm or = ppb Mass and volume units must match. (g & mL) or (Kg & L)
ppm & ppb An Olympic sized swimming pool contains 2,500,000 L of water. If 1 tsp of salt (NaCl) is dissolved in the pool, what is the concentration in ppm? Example Problem 1 1 teaspoon = 6.75 g NaCl or
ppm & ppb Example Problem 2 An Olympic sized swimming pool contains 2,500,000 L of water. If 1 tsp of salt (NaCl) is dissolved in the pool, what is the concentration in ppb? 1 teaspoon = 6.75 g NaCl or
A A A A A A A A A A A A B B B B B B B B + + Mole Fraction Mole Fraction(c) moles of A cA = sum of moles of all components moles of B cB = sum of moles of all components Since A + B make up the entire mixture, their mole fractions will add up to one.
Mole Fraction In our glass of iced tea, we have added 3 tbsp of sugar (C12H22O11). The volume of the tea (water) is 325 mL. What is the mole fraction of the sugar in the tea solution? (1 tbsp sugar ≈ 25 g) Example Problem 1 First, we find the moles of both the solute and the solvent. Next, we substitute the moles of both into the mole fraction equation.
Mole Fraction Example Problem 2 Air is about 78% N2, 21% O2, and 0.90% Ar. What is the mole fraction of each gas? First, we find the moles of each gas. We assume 100. grams total and change each % into grams. Next, we substitute the moles of each into the mole fraction equation.