Unit 6 EMPA Flashcards Preview

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Flashcards in Unit 6 EMPA Deck (8)
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0
Q

How would you remove impurities from an insoluble solid?

A

Filter and wash with water.

1
Q

Describe the process of recrystallisation.

A
  1. Dissolve in a minimum amount of solvent.
  2. Cool / crystallise.
  3. Filter.
2
Q

What is the formula of Tollen’s reagent?

A

+

[Ag(NH3)2]

3
Q

What is the maximum difference between two concordant results in a titration?

A

0.10 cm^3

4
Q

To how many decimal places should you record values taken from a burette?

A

To 2 dp, with the last digit being either 0 or 5.

5
Q

Describe an experiment to determine the melting point of a substance.

A

Place the substance in a capillary tube and heat it gently.

6
Q

In the observation task, what tells you that there are probably multiple observations you need to make?

A

“Add x, then add y”

“Then leave to stand for z minutes”

7
Q

What is the method for determining a melting point?

A

Use melting point apparatus
Heat the substance gently in a melting point tube in an oil bath
Slowly near the melting point