Acids and bases Flashcards
What does pH below 7 indicate?
An acidic substance/
What does a pH of 7 indicate?
A neutral substance.
What does a pH above 7 indicate?
An alkaline solution
What is the equation for dissociation of water?
H₂O ⇌ H⁺ + OH⁻
What do acids contain a higher concentration of?
H⁺ ions than OH⁻
What do Alkalis contain a higher concentration of?
OH⁻ ions than H⁺
What do neutral substances contain an equal concentration of.
OH⁻ and H⁺ ions
How can you recognise an acid?
The majority of acids end their name with the word “acid” such as hydrochloric acid and sulfuric acid.
What is difference between a base and an alkali?
Bases neutralise acids. Soluble bases are alkalis.
How can you recognise a base?
Bases tend to be metal hydroxides, metal oxides or metal carbonates. Ammonia is a common alkali.
What happens when an acid is diluted?
The pH increases towards 7, as the concentration of H⁺ ions decreases
What happens when an alkali is diluted?
The pH decreases towards 7, as the concentration of OH⁻ ions decrease.
What do soluble metals oxides do to form alkaline solutions
Dissolve in water
What do soluble non-metal oxides do to form acidic solutions?
Dissolve in water
What is a neutralisation reaction?
A neutralisation reaction is when a base and an acid react together to form a neutral solution and salt.
What happens when a base that ends with carbonate reacts with an acid (e.g. Metal carbonate)
It will form water, a salt and also carbon dioxide as it was a carbonate.
How do you name the first part of a salt formed in a neutralisation reaction?
The first part comes from the metal in the base (e.g., Sodium hydroxide forms sodium salts.)
How do you name the second part of a salt formed in a neutralisation reaction?
The second part of the name comes from the acid used (Sulfuric acid forms salts ending in sulfate)
What is a spectator ion?
A spectator ion is an ion which is present in a reaction but is not involved, it is only ‘observing’/’spectating’, and does not change state or charge.
