GRAVIMETRIC ANALYSIS Flashcards
What is the first step in heating to constant mass?
Heating a substance
This step involves applying heat to the substance to initiate the process of mass determination.
What is the purpose of cooling in a desiccator?
To prevent absorption of water
Cooling in a desiccator helps maintain the integrity of the sample by avoiding moisture uptake.
Cooling in a desiccator helps maintain the integrity of the sample by avoiding moisture uptake.
What is the process that follows heating and cooling in the constant mass determination?
Weighing
After cooling, the substance is weighed to assess any changes in mass.
What is the final step in the heating to constant mass process?
Repeating the steps until no further changes in mass are observed
This ensures that the mass is stable and accurately reflects the substance’s true mass.
What is gravimetric analysis used for?
To determine the mass of an element or compound in a substance
How is the substance converted in gravimetric analysis?
Into another substance of known chemical composition
This conversion is essential for isolating and purifying the target component for accurate measurement.
What are the two methods of conversion in gravimetric analysis?
Precipitation and volatilisation
What happens during precipitation conversion?
The substance undergoes a precipitation reaction
This results in the formation of a solid precipitate that can be isolated from the solution.
What is done with the precipitate after it is formed?
It is separated from the filtrate and washed
Washing the precipitate helps remove impurities and ensure accurate mass measurement.
What must be tested to ensure the precipitation reaction has gone to completion?
The filtrate
Testing the filtrate confirms that all the target substance has reacted and formed precipitate.
What is the next step after washing the precipitate?
Dried to constant mass and then weighed
This step is crucial for obtaining a precise mass of the precipitate.
What occurs during volatilisation conversion?
The substance is heated, and volatile products are evaporated
What must be recorded after heating to constant mass in volatilisation?
The final mass
Recording the final mass is essential for calculating the amount of substance present.
