7 – Standardising a Hydrochloric Acid Solution (LC 2027) (Leaving Cert Chemistry): Flashcards
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Practise the cards
15 cards from this deck
Definition of standardising a solution
Definition of standardising a solution
Finding its exact concentration
Why HCl solutions need regular standardising
Why HCl solutions need regular standardising
HCl gas escapes, decreasing concentration over time
Definition of a primary standard solution
Definition of a primary standard solution
A solution whose concentration is known very accurately
Why is used as primary standard
Why is used as primary standard
Stable, pure, doesn't absorb moisture from air
Mole ratio of to HCl in reaction
Mole ratio of to HCl in reaction
1:2 ratio
Indicator for HCl standardisation with
Indicator for HCl standardisation with
Methyl orange
Methyl orange colour in alkaline solution
Methyl orange colour in alkaline solution
Yellow
Methyl orange colour at end point (acidic)
Methyl orange colour at end point (acidic)
Red/pink
Volume of solution pipetted
Volume of solution pipetted
Definition of concordant results
Definition of concordant results
Results that agree within
Minimum number of accurate titrations needed
Minimum number of accurate titrations needed
At least three
How to add HCl near the end point
How to add HCl near the end point
Drop by drop
What to rinse the conical flask with
What to rinse the conical flask with
Deionised water only
Why wash down flask sides during titration
Why wash down flask sides during titration
Doesn't affect moles, ensures complete reaction
Purpose of rough titration
Purpose of rough titration
Gives idea of end point volume
