Preparation of reactive solutions

Introduction to bromatology (practices) |Analysis Protocols |Ref: 3.1 | |
|PREPARATION OF REACTIVE SOLUTIONS|


 
PURPOSE AND RATIONALE
To spek to establish a general procedure for preparation reactive solutions.

MATERIAL
Magnetic Stirrers.
Analytical Balance.
Top-loading balance.Desiccator.
Funnels
Drying stove.
Filter paper, fast.
Polyethylene bottles (of 1 liter) with screw cap.
Volumetric flasks of different volumes.
Filter paper.
Weighing bottle.
Pipettes ofdifferent volumes.
Plates heaters.
Rods.
Beakers of various volumes.


REAGENTS
(In addition to the practice specific)
Concentrated hydrochloric acid AG.
Distilled water.
Concentrated ammonia AG.METHODOLOGY
The appropriate methodology varies depending on the characteristics of each reactive solution to prepare.
 
CALCULATIONS
Based on the criterion of having data on the concentration ofthe solution that we want to prepare in grams / liter. To switch from normal to grams / liter applying the expression:
where "c" is the concentration in grams/liter, "N" is the normality and "pe" isthe equivalent weight. The amount to be weighed to prepare a volume "v" of concentration "c" is:

If the amount is too small, we can weigh a higher amount for subsequent dissolution. To prepare adiluted solution from another more concentrated, the volume of take concentrated solution is:


where "Vc" is the amount to be taken in concentrated solution, "Vd" the volume of diluted solution tobe prepared, "Cd" is the concentration (in grams/liter, molarity or normality) and "Cc" is the concentration of concentrated solution (in grams/liter, molarity or normality).

OBSERVATIONS
Alwaysfollow the precautions of use inherent in each product.

[pic]
 
Cuestionnaire 3.1.- Preparation of reactive solutions
1.- .- Define the following concepts:
a) reactive AG
b) titrated solution...