Chapter 11 Flashcards
acid + alkali
salt + water ( neutralisation)
acid + carbonate
salt + water + carbon dioxide (gas)
acid + metal
salt + hydrogen
how to test for hydrogen
lighted spleen should extinguish with a pop sound
how to test for CO2
Bubble into limewater. White precipitate should be formed.
alkali and acid difference
alkali:
- pH 8 - 14
-neutralises acids
-soapy feel
-bitter
Acid:
- pH 1- 6
- reacts with alkali, carbonate and metal
- sour
pH values
0 - 2 =red
2-5= orange
6 = yellow
7 = green
8 - 12 = blue
13 - 14= purple
physical changes
- easily reversable
- no new substances are formed
chemical changes
- usually not easily reversable
- one or more substances are formed
litmus paper
acid = red remain red, blue turn red
alkali = blue remain blue, red turn blue
neutral = red remain red, blue remain blue
thermal / decompose
chemical reaction that breaks down one substance into two or more new substances
( copper carbonate -heat-> copper oxide + carbon dioxide )
relationship between reactant and product
total number of each type of atom in reactant = total number of each type of atom in product
oxidation
a reaction with oxygen to form new substances
combustion
reaction with oxygen AND DURING THE REACTION, lots of heat/ light is generated ( fast process!)
( not all oxidation process are combustion but all combustion process are oxidation)
reactants and products
reactant:
substances that react with each other during a reaction
product:
substances that are formed after the reaction
