Medical Dosage Calculations A Dimensional Analysis Approach Eleventh Edition Chapter 8 Solutions

Learning Objectives 8.1 Find the strength of a solution as a ratio, as a fraction, and as a percent. 8.2 Determine the amount of solute in a given amount of solution. 8.3 Determine the amount of solution that would contain a given amount of solute. 8.4 Do the calculations necessary to prepare solutions from pure drugs. 8.5 Do the calculations necessary to prepare solutions for irrigations, soaks, and nutritional feedings. Slide 2 is list of textbook LO numbers and statements

Strength of a Solution (1 of 3)

Strength of a Solution (2 of 3) Solution strength can also be stated without explicit units of measurement. For example, a solution which is 1 part iodine in 2 parts of solution has strength of:

Strength of a Solution (3 of 3) Measure the Amount of Drug (Solute) in either g or mL Measure the Amount of the Solution in mL 1:100 NaCl solution has 1 g NaCl in 100 mL of the solution

Find the Strength (1 of 2) What is the strength of a 500 milliliter solution that contains 50 mL of iodine? 50 ml 500 ml

Find the Strength (2 of 2) What is the strength of a 200 milliliter solution that contains 50 g of NaCl?

Find the Amount of Solute in a Given Amount of Solution of Known Strength (1 of 2) How many grams of dextrose would you need to prepare 1000 milliliters of a 5% solution? Amount of solution is 1,000 milliliters.

Find the Amount of Solute in a Given Amount of Solution of Known Strength (2 of 2) Convert 1,000 mL of solution to g of dextrose

Finding the Amount of Solute (1 of 2)

Finding the Amount of Solute (2 of 2) Convert 250 mL solution to ? mL of Creosol

Find the Amount of Solution of Known Strength Containing a Given Amount of Solute (1 of 3) How many milliliters of a 20% magnesium sulfate solution will contain 40 grams of the solute magnesium sulfate? You want to convert the 40 grams of pure drug to milliliters of solution. 40 g = ? mL

Find the Amount of Solution of Known Strength Containing a Given Amount of Solute (2 of 3) In a 20% solution, there are 20 grams of solute per 100 mL of solution. So, the strength is But we want to convert from grams to milliliters. So we will use this form of the strength:

Find the Amount of Solution of Known Strength Containing a Given Amount of Solute (3 of 3) So, 200 mL of a 20% magnesium sulfate solution contains 40 g of magnesium sulfate.

Finding the Amount of Solute (1 of 3)

Finding the Amount of Solute (2 of 3) 1 4 Strength means (Sustacal) (Solution) 16 oz Solution = ? oz Sustacal

Finding the Amount of Solute (3 of 3) So, oz of full-strength Sustacal are needed to make 16 ounces of ¼ strength Sustacal.

Chapter Summary (1 of 4) The strength of a solution is the ratio of the amount of solute dissolved in the solution to the total volume of the solution. The strength of a solution may be expressed in the form of a ratio, fraction, or percentage.

Chapter Summary (2 of 4) The amount of solute dissolved in the solution should be expressed in milliliters if the solute is a liquid. The amount of solute dissolved in the solution should be expressed in grams if the solute is a solid or powder. The volume of a solution should be expressed in milliliters.

Chapter Summary (3 of 4) To determine the amount of solute contained in a given amount of a solution of known strength, use the strength as the known equivalence. To determine amount of a solution of known strength containing a given amount of solute, use the strength reciprocal as the known equivalence.

Chapter Summary (4 of 4) The strength of a particular solution may be written in many different forms. Example: 50g = 100mL (with units) Strength = 50g / 100mL = 50g per 100mL = 50g 100mL (without units) 50/100 strength = ½ strength = 1:2 = 50%