Acid-base Titrations Flashcards Preview

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Flashcards in Acid-base Titrations Deck (15)
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1

Titration

Accurately measure volume of 1 solution that reacts exactly with another solution
Used for finding concentrations, identification of unknowns, substance purity

2

Volumetric flask error
100cm3

+- 0.20cm3

3

Volumetric flask error
250cm3

+- 0.30cm3

4

Pipette error
10cm3

+- 0.04cm3

5

Pipette error
25cm3

+- 0.06cm3

6

Burette error
50cm3

+- 0.10cm3

7

How to use burrette

Bottom of meniscus to nearest half division
Run excess solution through tap to remove air

8

How to use indicator

Few drops only, indicator is slightly acidic

9

How to use mean titres

Concordant titres 0.10 for accuracy

10

How to do titration calculations

Find mean titres
Stoichiometry
Concentration equation

11

How to work out the moles used in the titration

Multiply the moles by the scale factor of the volumetric flask volume to find the actual number of moles used in the titration

12

How to calculate the percentage by mass

Percentage by mass= mass of compound/ mass of total x 100

13

How to do back titrations

Use all information given to you
Use balanced equations

14

How to balance half equations in acidic conditions

Balance atoms other than H and O
Balance oxygen by adding water
Balance hydrogen by adding H+
Balance charges by adding electrons to +ve side

15

Combining half equations

As reduction and oxidation happen at the same time, electrons should be equal on both sides