Revision Chemistry Flashcards
Explain the properties of a physical change.
A change in state/ arrangement of particles and can be turned back to its original form. It can be a change in texture, shape, temperature, and a change in the state of matter.
What is boiling/evaporation?
To change state from a liquid to a gas.
What is a Catalyst?
Substances that increase the rate of a reaction
without becoming used up.
Chemical Reaction
Procedure that produces new chemicals; same as chemical change
Collison Theory
In collision theory, the more collisions that
happen between the particles, the more likely
it is that they will react.
Concentration
The number of particles trapped
in a small area
Condensation
When a gas becomes a liquid
Corrosion
The damage caused to metal in it’s environment
Enzyme
A chemical that helps chemical reactions happen; a type of catalyst.
Fume
A gas or vapour that has a strong sense of spell or is dangerous to breathe in.
Lattice
Three-dimensional arrangement of particles in a regular pattern.
Melting
To change state from solid to liquid.
Product
Substance obtained at the end of a chemical reaction.
Reactant
Substance that reacts or changes to produce
new substances.
Sublimation
Change of state straight from a solid to a gas. (Dry Ice).
Vaporise/Evaporation
To change from a liquid to gas; same as evaporate.
Vapour
A gaseuous form of a substance when it is usually solid in room temperature.
Volatile
A substance that easily becomes a gas.
Deposition
Change of state straight from gas to solid (Dry Ice).
Example of chemical change (Rusting)
Rusting of metal also known as oxidisation is a chemical change as it is irreversable.
Example of chemical change (burning toast)
When the toast is burnt it is irreversible. Its reactant is toast and heat and the product is burnt toast.
Example of physical change (Nitrogen).
It is a gas but it can still be frozen at a very low temperature to create dry ice. it can be reheated to become nitrogen gas again making it a physical change.
Explain how temperature may affect reaction rate.
When the reactants particles are heated, they move faster and faster resulting in larger collisons.
Explain how concentration may affect reaction rate.
More concentrated substances will
react more easily, again due to the collision
theory. A more concentrated substance
has more particles available to collide with
particles from another substance.
Explain how dyes used to be made and how they are made now.
Use to be made from welks which are snails which created a puple dye that could change the colour of wool or cotton… as usually they would be their natural colour but thousands of snails would be needed just to coulour one piece of clotheing as to why the snails nearly went extinct. They the used crusted insects to dye a piece of clothing red. Then William perkins created the first type of artificial dye in 1878.
The effect of particle size with reaction rates.
The smaller the size of the
particles, the faster the rate of the reaction. Smaller particles have a
greater total surface area, which means that the
particles have a greater chance of interacting
with each other
Combustion
Burning- a substance reacts rapidly with oxygen and gives off heat.
