Preparation of Liquid chemical compounds

For example /preparation of 0.1N Hydrochloric acid (HCl).

Volumetric Analysis

Prepared by: Hemn Khalid QadirAt March 2015 to 1st stage in college of pharmacy

Expressing concentration of solution

Molarity : is the number of moles of solute dissolved in one liter of solution. The units, therefore are moles per liter, specifically it's moles of solute per liter of solution.

Normality : is the number of equivalents of solute dissolved in one liter of solution. The units, therefore are equivalents per liter, specifically it's equivalents of solute per liter of solution.

M.WtEq.Wt = ------------ nn = No. of (H) atoms for acidsfor HCl n=1 n = No of OH groups for basesfor NaOH n=1

n = No of Cation atoms (M+) for salts for Na2CO3 n= 2

n = No. of gained or lost electrons for oxidants and reductantsfor KMnO4 n= 7

•Normality of Concentrated Reagents

Q/Describe the preparation of 900 mL of 3.00 M HN03 from the commercial

reagent that is 70.5% HN0 3 (w/w) and has a specific gravity of 1.42.

Q/How to make 0.1N HCl from concentrated HCl to 250 ml D.W?

PROCEDURE:-------------1.First of all, fill the volumetric flask about halfway with distilled water to avoid violent reactions. NEVER add water to concentrated acid.

2.Choose a clean pipette of suitable size and transfer the liquid to the volumetric flask. When the whole solution has been drained, touch the tip of the pipette to the side of the volumetric flask to allow the last of the liquid to drain out. DO NOT blow out the remaining solution.

3.Very carefully fill the flask to the mark on the neck of the flask, using a dropping pipette to add the last few milliliters of liquid. Mix your solution thoroughly, by inverting the flask and shaking.

4.Transfer the prepared solution to a clean, dry storage bottle and label it.

SAFETY NOTES:-------------- When making chemical solutions, always use the appropriate safety equipment.- As a general rule, always add the more concentrated solution to the less concentrated solution.- All chemicals that you are unfamiliar with should be treated with extreme care and assumed to be highly flammable and toxic.

Basic Laboratory Safety