BY CALCULATIONS HOW WOULD I PREPARE 200ml of 80% GLYCEROL (V/V)

80% glycerol (v/v) means 80 mL glycerol/100 mL solution.

So place 80 mL glycerol in a 100 mL volumetric flask and add water to make 100 mL. (That makes only 100 mL soln--I assume you can double all that and use a 200 mL volumetric flask?)

160ml

To prepare 200 mL of 80% glycerol (v/v) solution, you will need to understand the concept of volume/volume percent concentration and perform some calculations. Let's break it down step by step:

Step 1: Understand the concept
Volume/volume percent concentration (v/v %) is a way to express the concentration of a solute in a solution. It represents the volume of solute (glycerol) per 100 volume units of the solution. For example, a 20% solution of glycerol means that there are 20 mL of glycerol in every 100 mL of the solution.

Step 2: Calculate the amount of glycerol needed
To find out how much glycerol you need to prepare an 80% glycerol solution, you can use the following formula:

Amount of Glycerol (mL) = (Volume of Solution (mL) * Volume/Volume %) / 100

In this case:
Amount of Glycerol (mL) = (200 mL * 80) / 100
= 160 mL

So, you will need 160 mL of glycerol.

Step 3: Determine the remaining volume
Since you want to prepare a 200 mL solution and you have determined that you need 160 mL of glycerol, the remaining volume will be:

Remaining Volume (mL) = Volume of Solution (mL) - Amount of Glycerol (mL)
= 200 mL - 160 mL
= 40 mL

You will need 40 mL of another solvent (such as water) to make up the total volume.

Therefore, to prepare 200 mL of 80% glycerol (v/v) solution, measure 160 mL of glycerol and add it to 40 mL of another solvent (e.g., water) to reach the desired volume.