Here’s a explanation of precipitation gravimetry:
Meaning
Precipitation gravimetry is a type of gravimetric analysis where the substance to be measured is turned into an insoluble solid (precipitate) by adding a suitable reagent.
The solid is then filtered, dried, and weighed to find how much of the substance was in the sample.
How it works
- Dissolve the sample in water.
- Add a reagent to form an insoluble precipitate.
- Filter and wash the precipitate to remove impurities.
- Dry or ignite it to constant weight.
- Weigh the solid and calculate the amount of the element or compound present.
Example
To find chloride (Cl⁻) in a solution:
- Add silver nitrate (AgNO₃) → it forms silver chloride (AgCl), a white solid.
- Filter, dry, and weigh AgCl.
- From the weight of AgCl, calculate how much chloride was in the sample.
Why it’s useful
- Gives very accurate results.
- Simple equipment needed.
- Useful for determining metals and ions that form insoluble compounds.
In short:
Precipitation gravimetry measures an element by forming, purifying, and weighing a solid precipitate that contains it.