gravimetric analysis Flashcards

1
Q

what does heating to constant mass involve

A
  • heat a substance
  • allow to cool in a dessicator to prevent absorption of water
  • weigh
  • repeat the steps of heating and cooling and weighing until no further changes in masses are observed
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2
Q

what is gravimetric analysis used for

A

determining the mass of an element or compound in a substance

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3
Q

how can you readily isolate and purify a substance

A

by converting it into another substance of known chemical composition

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4
Q

how can you convert a substance into another substance of known composition

A

through precipitation or volatilisation

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5
Q

what occurs in precipitation conversion

A
  • the substance undergoes a precipitation reaction
  • precipitate is separated from the filtrate and the filtrate is tested to ensure the reaction has gone to completion
  • the precipitate is washed and dried to a constant mass and then weighed
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6
Q

what occurs in volitalisiation conversion

A
  • the substance is heated and any volatile products (often water) are evaporated
  • the substance is heated to a constant mass and the final mass is recorded
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