PPM (parts per million) PPM = grams solute X 1,000,000 PPM = grams solute X 1,000,000 used when solute is present in very small amounts (The Regents don ’ t follow this rule) used when solute is present in very small amounts (The Regents don ’ t follow this rule) like % except you multiply by 1,000,000 instead of 100 grams solution

LET’S PRACTICE: About g of O 2 can be dissolved in 100 mL of water at 20 o C. Express in ppm. [Memorize: 1 mL water has mass of 1 g] What is the solvent? Water How much solvent is there? 100 mL = 100 g How much solute is there? g How much is the total solution? 100 g g = g

LET’S PRACTICE: About g of O 2 can be dissolved in 100 mL of water at 20 o C. Express in ppm. THE EQUATION ppm = g X 1,000, g ppm = 43 ppm [Memorize: 1 mL water has mass of 1 g]

NOW YOU TRY: CO 2 gas has solubility of g/100 g water at 40 o C; Express in parts per million ppm = g solute X 1,000, g solution = 971 ppm

HERE’S ANOTHER: What is the concentration in ppm of a solution with 30.0 g NaNO 3 in 70.0 g water? ppm = 30.0 g NaNO 3 X 1,000, g solution = 300,000 = 3.0 X 10 5 ppm

LAST ONE: How many grams of KOH are needed to be dissolved in water to make grams of a 10.0 ppm solution? 10 ppm = X grams KOH X 1,000, g solution X = 0.02 grams KOH