Gravimetric Analysis Flashcards Preview

Advanced Higher Chemistry: Unit 3 - Researching Chemistry > Gravimetric Analysis > Flashcards

Flashcards in Gravimetric Analysis Deck (7)
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1
Q

What is gravimetric analysis?

A

Analytical determination of the mass of an element or compound in a substance by chemically changing the substance

2
Q

Describe gravimetric analysis.

A

Gravimetric analysis is used to determine the mass of an element or compound in a substance. The substance is converted into a product of known chemical composition, which can be readily isolated and purified. The conversion can either occur through precipitation or volatilisation.

3
Q

Describe gravimetric analysis through precipitation reaction.

A

In precipitation conversion the substance undergoes a precipitation reaction. The precipitate is then separated from the filtrate and the filtrate tested to ensure the reaction has gone to completion. The precipitate is washed, dried and then weighed.

4
Q

Describe gravimetric analysis through volatilisation reaction.

A

In volatilisation conversion the substance is heated and any volatile products are driven off. It is heated to constant mass and the final mass recorded.

5
Q

What is meant by heating to a constant mass?

A

Substance heated and weighed. This is repeated until the mass remains constant.

6
Q

What is the purpose of a desiccator?

A

To stop water getting in and prevent moisture absorption.

7
Q

What is meant by ‘weighing approximately accurately’?

A

the measured value doesn’t need to be exactly the theoretical value. However, the value measured has to be accurate.