Acids And Alkalis Flashcards
What does the skull symbol as a hazard symbol mean?
Toxic
What is a neutralisation reaction?
When an acid reacts with a base to produce a neutral solution of salt and water
If it is soluble in water, is it an alkali or base?
Alkali
If it is not soluble in water, is it a base or alkali?
Base
What is an alkali?
A base that is soluble in water
What does an indicator do?
Tells us the ph of a substance
Name 4 indicators
Litmus
Methyl orange
Phenolphthalein
Universal indicator
What’s a base?
A base is a substance that neutralises acids to form a salt and water only
Metal oxide + acid –> ? + ?
Salt + water
During neutralisation, how is water formed?
Hydrogen ions in acid combine with oxide ions to form water
During neutralisation, how is ph neutralised?
Through the removal of hydrogen ions
During neutralisation, how is salt formed?
By replacing the hydrogen ions with metal ions
What salt does hydrochloric acid form?
Chloride
What salt does sulphuric acid form?
Sulfate
What salt does nitric acid form?
Nitrate
What is used to prepare samples of different soluble salts?
An acid and insoluble metal oxide
What can an acid and insoluble metal oxide be used to do?
To prepare sample of different soluble salts
How can tin oxide be prepared?
By reacting tin(II)oxide with hydrochloric acid solution
In preparing soluble salts, what precaution is taken?
Excess of base is always added to ensure that all acid is used up
In preparing soluble salts, how is it made sure that the filtered salt is pure?
Mixture is filtered to remove unreacted metal oxide from the filtrate, leaving salt and water
In preparing soluble salts, how is a solid sample of the salt obtained?
Water evaporates, so crystallisation of the salt occurs
In preparing soluble salts, how is it made sure that the biggest amount of salt possible is formed?
Water is evaporated slowly, the slower it evaporates the larger the crystals that will form
What is concentration?
How many particles are dissolved in given volume of liquid
What does amount of hydrogen ions result in in terms of acidity?
The more acidic
What does the level of concentration result in in terms of pH?
Lower the concentration, the higher the pH
How do strong acids dissociate?
They completely dissociate (split up
How do weak acids dissociate?
Partially dissociate (only some split up)
What are the three strong acids?
Sulfuric acid, hydrochloric acid and nitric acid
What are the three weak acids?
Ethanoic acid, citrus acid, carbonic acid
What’s the formula of sulfuric acid?
H(little2)SO(little4)
What’s the formula of hydrochloric acid?
HCl
What’s the formula of nitric acid?
HNO(little3)
What’s the formula of ethanoic acid?
CH(little3)COOH
What’s the formula of citric acid
C(little6)H(little8)O(little7)
What’s the formula of carbonic acid?
H(little2)CO(little3)
What does a double headed arrow in a chemistry equation mean?
That it only partially dissociates
What charge will hydrogen always be?
Positive
How many acid particles do concentrated acids have dissolved in their water?
Lots of acid particles dissolved in the water
How many acid particles do dilute acids have dissolved in their water?
Only a few acid particles dissolved in the water
What is the equation for concentration?
Concentration= amount dissolved/volume
What’s the two SI units for concentration?
g/dm^3 or gdm-3
What’s SI units for amount dissolved (in concentration)?
g
What’s SI units for volume(in concentration)?
dm^3
1dm^3=?cm^3
1,000
What’s an acid?
A chemical that releases H+ions in water
What’s a base?
A base is any chemical that neutralises acids to make a salt and water only