chap 8: acids and bases Flashcards
what is an acid?
it is a substance that dissociates in water to produce hydrogen ions, H+
list 3 properties of acids
- sour taste
- produce ions when dissolved in water hence acids are able to conduct electricity (due to presence of mobile ions
- turns blue litmus paper red
what is the product of acid and reactive metals?
salt + hydrogen gas (H2)
how to check if an acid + metal reaction has taken place?
effervescence observed and metal dissolves
how to test for hydrogen gas?
use a lighted splint. in the presence of hydrogen gas, the lighted splint will extinguish with a ‘pop’ sound
what are some unreactive metals?
lead, copper, silver, gold
what are metals that are too reactive?
potassium, sodium, calcium
what is the product of acid + base
salt + water (H2O)
how to check if an acid reaction with base has occured?
solid base dissolves. resulting mixture feels warm to touch.
what is the reaction, where water is the only product other than salt?
neutralisation
what is the product of the reaction of acid with carbonates?
salt + carbon dioxide (CO2) + water (H2O)
how to check if an acid + carbonate reaction has taken place?
effervescence observed and metal carbonate dissolves
how to test for carbon dioxide gas?
bubble gas into limewater (calcium hydroxide). in the presence of carbon dioxide gas, white precipitate will be formed in the limewater. the white precipitate that forms is calcium carbonate.
what does the strength of an acid refer to?
strength of an acid refers to the extent of dissociation / ionisation of the acid when dissolved in water
what is a strong acid?
a strong acid is an acid that completely dissociates/ionises in water to give a high concentration of hydrogen (H+) ions.
what is a weak acid?
a weak acid is an acid that partially dissociates/ionises in water to give a low concentration of hydrogen (H+) ions