Reactivity Flashcards
melting salt: chemical or physical change?
Physical
Burning petrol: Chemical or physical change?
Chemical
Separating sugar from water in a sugar-water solution: Chemical or physical change
Physical
Boiling water : Chemical or physical change
Physical
Freezing food: Chemical or physical change
Physical
Separating sand from a mixture sand and water by filtration: Chemical or physical change
Physical
Puddles evaporating: Chemical or physical change
Physical
Heating silver oxide to form silver and oxygen: Chemical or physical change
Chemical
Lighting a match
Chemical
Respiration in cells : Chemical or physical change
Chemical
Nail varnish drying: Chemical or physical change
Physicalllllllllllll
Leaf rotting : Chemical or physical change
Chemical
Wax burning: Chemical or physical change
Chemical
Photosynthesis in leaves:: Chemical or physical change
Chemical
Condensing stream
Physical
Define implosion
An object destroyed by collapsing in on itself
What is a physical change
A change in which no new substances are formed
Give 3 qualities of a physical change
- do not make new substances
- are often easy to reverse
- the substances may change state or just be mixed together
Give 4 examples of a physical change
Melting
Boiling
Condensing
Freezing
Give 3 qualities of a chemical reaction
-always make at least one new substance
-are usually difficult to reverse
-the new substances have different properties from the original substance
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Give 3 examples of a physical change
Combustion
Neutralisation
Thermal decomposition
How is gas pressure caused
By the force of the particles hitting the walls of the container
Why does increasing the temp. increase pressure
The particles move faster and they hit the walls of the container more often with more force
Why does increasing the number of particles in the container increase pressure
The particles are closer together and hit the walls of the container more often
Why does decreasing the volume of the container increase pressure
The particles are closer together and hit the walls of the container more often
Most metals react with oxygen from the air to create what? What is the name of the reaction?
They create metal oxides, this is called an oxidation reaction
How does potassium react with oxygen, water and dilute acid?
Fire,fire, EXPLOSION
How does sodium react with oxygen, water and dilute acid?
Fire, reacts very quickly and explosion
How does lithium react with oxygen, water and dilute acid?
Fire, reacts quickly, reacts very quickly
How does calcium react with oxygen, water and dilute acid?
Fire, reacts quickly, reacts very quickly
How does magnesium react with oxygen, water and dilute acid?
Fire, reacts, reacts quickly
How does aluminium react with oxygen, water and dilute acid?
Reacts very quickly, slow or partial reaction
How does gold react with oxygen, water and dilute acid?
No reaction, no reaction, no reaction
Iron and steel need what to rust?
Air and water
What makes iron and steel rust quicker
Salt
How can rusting be prevented
- The physical barrier to stop the air and water being in contact with iron
- sacrificial protection in which blocks of a more reactive metal such as zinc or magnesium are attach to the iron and they then corrode instead of the iron
What is a hydrocarbon?
These substances contain only hydrogen and carbon
What do hydrocarbons supply if burnt?
Carbon dioxide and water
How do you test for oxygen?
It relightes a glowing splint
What is a displacement reaction
In a displacement reaction a more reactive metal takes the place of a less reactive metal in a compound.
Here is an example of a displacement reaction:
Aluminium +iron oxide—-> iron+aluminium oxide
Why does this happen?
Aluminium takes the place of iron as it is a more reactive metal and forms stronger bonds with oxygen
What is the opposite of oxidation?
Reduction- the loss of oxygen
