Calculating concentrations

Different ways to express concentration: Number of grams of solute per liter of solution (g/L) Number of grams of solute per 100 ml of solution (%mass /volume = %m/V) Number of millilitres of solute per 100 ml of solution (% volume/volume = %V/V) Number of grams of solute per 100 grams of solution (% mass/ mass = %m/m) c = amount solute amount solution

grams of solute per liter of solution (g/L) c = amount solute amount solution c = mass of solute volume of solution c = m v in g in L

conversions L = L = 10 mL = 1 mL = 1000 mg = 100 mg = g = g = 1000 mL 100 mL L L g g 10 mg 1 mg

mg 19 g sugar m = 19 g v = 200 ml c = 19 g 0.2 L c = m v c = 95 g /L m = 53.5 mg v = 1 L c = m v g 1 L c = g /L known: formula: known: formula: = 0.2 L = g

example How much sugar do you need if you want to make 20 ml of a sugar solution with a concentration of 50 g/L? c = m v c = 50 g/L v = 20 mL = 0.02 L m = ? 50 g/L = x g 0.02 L x = 1 g known:formula: m = 1 g

Different ways to express concentration: Number of grams of solute per liter of solution (g/L) Number of grams of solute per 100 ml of solution (%mass /volume = %m/v) Number of millilitres of solute per 100 ml of solution (% volume/volume = %v/v) Number of grams of solute per 100 grams of solution (% mass/ mass = %m/m) c = amount solute amount solution

grams of solute per 100 ml of solution: % m/v 3.25 % MF  1 % MF  3.25 g milk fat 100 ml milk 1 g milk fat c = amount solute amount solution

grams of solute per 100 ml of solution: % m/v g Sodium fluoride 100 ml of tooth paste

example Determine the concentration of a solution of 20 g solute in 250 mL final solution in % m/v. m = 20 g v = 250 mL c = m v x 20 g 250 mL x g = 20 g × 250 mL 100 mL x =8g c = 8 %m/v known:formula: c = xg /100 mL = x %m/v 100 mL = g

Different ways to express concentration: Number of grams of solute per liter of solution (g/L) Number of grams of solute per 100 ml of solution (%mass /volume = %m/v) Number of millilitres of solute per 100 ml of solution (% volume/volume = %v/v) Number of grams of solute per 100 grams of solution (% mass/ mass = %m/m) c = amount solute amount solution

100 ml of vinegar 5 ml acetic acid milliliters of solute per 100 ml of solution, % v/v 100 ml of beer 7.9 ml ethanol

example How much ethanol (in mL) is there in a 750 mL bottle of wine with an alcohol concentration of 12 %v/v? c = amount solute amount solution 12 mL x mL known: c = 12 mL / 100 mL v = 750 mL amount of solute = x mL c = 100 mL = 750 mL x = 90 mL amount of solute in 750 mL = 90 mL

Different ways to express concentration: Number of grams of solute per liter of solution (g/L) Number of grams of solute per 100 ml of solution (%mass /volume = %m/v) Number of millilitres of solute per 100 ml of solution (% volume/volume = %v/v) Number of grams of solute per 100 grams of solution (% mass/ mass = %m/m) c = amount solute amount solution

grams of solute / 100 g of solution: % m/m 18 Ka = 750 / g gold 100 g alloy = 75 % m/m

example What is the % m/m carbon concentration of steel made by adding 3g of Carbon to 147 g of iron? c = amount solute amount solution known: c = x g / 100 g amount of solution = g amount of solute = 3 g c = x g 100 g = 3 g 150 g x = 2 g c = 2 g / 100 g = 2 % m/m

Homework Work book page 8 / 9; # 1, 2, 3, 6, 7 Conversion work sheet

c = amount solute amount solution 100ml