Chemical Changes 1+2 Flashcards
what are the three most common acids?
- hydrochloric acid (HCl)
- Sulfuric acid (H2SO4)
- nitric acid (HNO3)
Types of salt that can form from the acids
- nitrate
- cholide
- sulfate
What can salts be used for?
- seasoning food
- dissolved in drinking water
- perserve food
- fertilizers (sulfate and nitrate salts)
What kind of reaction is the reaction between acids and metals?
- redox reaction
- (oxidation and reduction reaction taking place at the same time)
What is oxidation?
- gain of oxygen or losing of electrons of a substance in a reacton
What is reduction?
- losing of oxygen, gaining of electrons or gaining hydrogen by a substance in a reaction
what do all acids have?
hydrogen ions
What is the difference between an alkali and a base?
- alkalis are soluble, they can dissolve in water
- all alkalis are bases but not all bases are alkali
How do you identify a base?
- name ends with carbonate or oxide
How do you identify an alkali?
- if the metal is in group 1/2 ending with hydroxide
How do you identify a salt?
- ends with sulfate/ nitrate/ chloride
compound ions names
- hydroxide (OH-)
- nitrate ion (NO3-)
- sulfate ion (SO4 2-)
- carbonate ion (CO3 2-)
What is neutralisation?
When acids are neutralised by alkalis and bases to produce salt and water, and by metal carbonates to produce salts, water and carbon dioxide
What does alkalis and bases produce when they neutralise acids?
Water and salt
What do metal carbonates produce when they react with acid?
Salt, water, and carbon dioxide
What salt does the three most common acids make
Hydrochloric acid - chloride
Sulfuric acid - sulfate
Nitric acid - nitrite
How do you make pure, dry samples of soluble salts?
- measure aicd using measuring cylinder and pour it into beaker
- gently heat the acid by placing it on a bunsen burner and a tripod (speeds up reaction)
- take acid off bunsen and add spatulas of the alkali/ base until the powder at the bottom of the beaker. (to make sure that the alkali/ base is in excess) the solution should turn into a different colour (blue for copper sulfate)
- remove the excess copper oxide by filtering it using a funnel and filitering paper (to remove excess copper oxide)
- pour the solution into evaporating basin and heat over a beaker of boiling water(if the solution is heated directly the crystals will break down)
- take evaporating basin off the water bath once half of the solution is gone and leave it out at room temp to let it evaporate naturally (larger crystals can form)
- after water has evaporated entirely, put crystals on filiter paper (to make sure that it is completely dry)