Biol 189 Lab 3: Concentrations and Solutions

Dissociation

the separation of atoms of a molecule or compound.

Dissolving

when a solvent surrounds individual solute atoms or molecules.

concentration

a measure of how much of a solute is dissolved per unit of solution

You have 500 mL of a 10% (%v/v) bleach solution. How much bleach is in your solution?

50 mL

You dissolve 60 mL of ethanol in water and add enough water until the total volume is 400 mL. What is the volume percent concentration of your ethanol solution?

15 % v/v ethanol

Rubbing alcohol (isopropyl alcohol solution) usually has a %v/v concentration of 70%. How much isopropyl alcohol must have been used to make 2 L of the solution?

1400 mL

Saline solution in IV fluids has a 0.9% NaCl (%m/v) concentration. How much NaCl must you add to

create a 1 L IV bag?

9 g

An intravenous sugar solution used to treat low blood sugar has a 5% (m/v) concentration of glucose.

200 mL is administered to a patient. What mass of glucose did the patient receive from the solution?

10 g

While making a 10%m/v NaCl solution, a student weights out 10 g of NaCl and measures 100 mL of

water. The student then pours the NaCl into the water and stirs until it is dissolved. What mistake(s) did

the student make while preparing this solution?

The student was supposed to add the solvent(water) gradually to the solute until it reaches 100 mL. If the student just poured the solute into the water, the solution is more than 100 mL, which also means the concentration will be less than 10% m/v.

Standard curve

a type of graph used to compare unknown samples to those that are known