PPM parts per million PPM grams solute X

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

LET’S PRACTICE: About 0. 0043 g of O 2 can be dissolved in 100 m. L of water at 20 o. C. Express in ppm. [Memorize: 1 m. L water has mass of 1 g] • What is the solvent? • Water • How much solvent is there? • 100 m. L = 100 g • How much solute is there? • 0. 0043 g • How much is the total solution? • 100 g +. 0043 g = 100. 0043 g

LET’S PRACTICE: About 0. 0043 g of O 2 can be dissolved in 100 m. L of water at 20 o. C. Express in ppm. [Memorize: 1 m. L water has mass of 1 g] THE EQUATION ppm = 0. 0043 g X 1, 000 100. 0043 g ppm = 43 ppm

NOW YOU TRY: CO 2 gas has solubility of 0. 0972 g/100 g water at 40 o. C; Express in parts per million ppm = 0. 0972 g solute X 1, 000 100. 0972 g solution = 971 ppm

HERE’S ANOTHER: What is the concentration in ppm of a solution with 30. 0 g Na. NO 3 in 70. 0 g water? ppm = 30. 0 g Na. NO 3 X 1, 000 100. 0 g solution = 300, 000 = 3. 0 X 105 ppm

LAST ONE: How many grams of KOH are needed to be dissolved in water to make 2000. 0 grams of a 10. 0 ppm solution? 10 ppm = X grams KOH X 1, 000 2000. 0 g solution X = 0. 02 grams KOH