Solutions

Percent Concentration

Percent Concentration

Describes the amount of solute dissolved in 100 parts of solution

amount of solute

100 parts solution

Mass-Mass % Concentration

mass/mass % = g solute x 100% 100 g solution

Mixing Solute and Solvent

Solute + Solvent

4.0 g KCl 46.0 g H2O

50.0 g KCl solution

Calculating Mass-Mass %

g of KCl = 4.0 g

g of solvent = 46.0 g

g of solution = 50.0 g

%(m/m) = 4.0 g KCl (solute) x 100 = 8.0% KCl

50.0 g KCl solution

Grams, Moles & %Composition

A solution contains 15 g Na2CO3 and 235 g of

H2O? What is the mass % of the solution?

1) 15% (m/m) Na2CO3

2) 6.4% (m/m) Na2CO3

3) 6.0% (m/m) Na2CO3

Solution

mass solute = 15 g Na2CO3

mass solution = 15 g + 235 g = 250 g

%(m/m) = 15 g Na2CO3 x 100

250 g solution

= 6.0% Na2CO3 solution

Mass-Volume %

mass/volume % = g solute x 100% 100 mL solution

Moles & Volume & %Composition

An IV solution is prepared by

dissolving 25 g glucose

(C6H12O6) in water to make 500.

mL solution. What is the

percent (m/v) of the glucose in

the IV solution?

1) 5.0% 2) 20.% 3) 50.%

Solution

1) 5.0%

%(m/v) = 25 g glucose x 100

500. mL solution

= 5.0 %(m/v) glucose solution

Writing Factors from %

A physiological saline solution is a 0.85% (m/v) NaCl solution.

Two conversion factors can be written for the % value.

0.85 g NaCl and 100 mL NaCl soln

100 mL NaCl soln 0.85 g NaCl

% (m/m) Factors

Write the conversion factors for a 10 %(m/m) NaOH solution

NaOH and NaOH soln

NaOH soln NaOH

% (m/m) Factors

Write the conversion factors for a 10 %(m/m) NaOH solution

NaOH and NaOH soln

NaOH soln NaOH

10 g

10 g100 mL

100 mL

Moles, Volume & %Composition

Write two conversion factors for each of the following solutions:

A. 8 %(m/v) NaOH

B. 12 %(v/v) ethyl alcohol

Solution

Write conversion factors for the following:

A. 8 %(m/v) NaOH

8 g NaOH and 100 mL__100 mL 8 g NaOH

B. 12 %(v/v) ethyl alcohol

12 mL alcohol and 100 mL 100 mL 12 mL alcohol

Using % Factors

How many grams of NaCl are needed to prepare 250 g of a 10.0% (m/m) NaCl solution?

Complete data:____________ g solution

____________% or (______/_100 g_) solution

____________ g solute

Clculation Using % Factors

250 g solution

10.0% or (10.0 g/100 g) solution

? g solute

250 g NaCl soln x 10.0 g NaCl = 25 g NaCl100 g NaCl soln

Calculations using %Compostion

How many grams of NaOH do you need to measure out to prepare 2.0 L of a 12%(m/v) NaOH solution?

1) 24 g NaOH

2) 240 g NaOH

3) 2400 g NaOH

Solution

2.0 L soln x 1000 mL = 2000 mL soln

1 L

12 % (m/v) NaOH = 12 g NaOH

100 mL NaOH soln

2000 mL x 12 g NaOH = 240 g NaOH

100 mL NaOH soln

Moles, Volume & %Composition

How many milliliters of 5 % (m/v) glucose solution are given if a patient receives 150 g of glucose?

1) 30 mL

2) 3000 mL

3) 7500 mL

Solution

5% m/v factor

150 g glucose x 100 mL = 3000 mL

5 g glucose