Making soluble salts (Edexcel GCSE Chemistry Combined Science): Flashcards
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Type of base used in Method 1 for making soluble salts
Type of base used in Method 1 for making soluble salts
Insoluble base (e.g. metal oxide or carbonate)
Why heat acid in fume cupboard (Method 1)?
Why heat acid in fume cupboard (Method 1)?
To avoid inhaling acid fumes
How to know all acid is neutralised in Method 1?
How to know all acid is neutralised in Method 1?
Add base in excess until no more reacts
Equipment to filter excess base from salt solution
Equipment to filter excess base from salt solution
Filter paper and funnel
Final step to obtain salt crystals
Final step to obtain salt crystals
Evaporate water, cool to crystallise, filter & dry
Definition of an alkali
Definition of an alkali
A soluble base
Why use titration in Method 2 (acid + alkali)?
Why use titration in Method 2 (acid + alkali)?
Both alkali & salt are soluble; could contaminate salt
Equipment to measure set volume of acid in titration
Equipment to measure set volume of acid in titration
Pipette
What shows when acid is neutralised in titration?
What shows when acid is neutralised in titration?
Indicator changes colour
What is the 'end point' in titration?
What is the 'end point' in titration?
When the acid has been neutralised
Why repeat titration without indicator?
Why repeat titration without indicator?
To make pure salt (avoid contamination with indicator)
Why not use universal indicator for titrations?
Why not use universal indicator for titrations?
Colour change is too gradual
Phenolphthalein colour in alkali vs neutral
Phenolphthalein colour in alkali vs neutral
Pink in alkali, colourless when neutral
Methyl orange colour in acid vs neutral/alkali
Methyl orange colour in acid vs neutral/alkali
Red in acid, yellow in neutral/alkali
Why measure acid & alkali volumes precisely?
Why measure acid & alkali volumes precisely?
To avoid excess reactants contaminating the salt