Objective: To explain how to produce percent solutions.
Safety Considerations: To avoid accidental overdose, always label all containers
Materials To Add To Your Lab Bench:
(Note :Before you begin make sure you obtain pure water)
Step 1: Calculate the desired volume of starting solution needed to make the final percentage.
Example: A 70% EtOH solution from 100% EtOH
100%/50mL = 70%/x mL
100%*x = 50mL*70%
Step 2: Calculate the desire amount of water to get a total volume of 50mL
50 mL - 35mL EtOH = 15 mL dH2O
Step 3: Measure 35mL of 100%EtOH and 15mL of dH2O using a 100mL graduated cylinder
Step 4: Mix the two liquids from step 3 together.
(*This would make an extra dry martini)
Procedure: 50 mL of 70% EtOH from 95% Ethanol*
Step 5: Repeat Steps #1 - 4.
Example: A 70% EtOH solution from 95% EtOH
95%/50mL = 70%/x mL
x=36.8 mL EtOH
Obtain the desired final volume (50mL) by adding the
appropriate volume of dH2O (in this case, 13.2mL)