Chemical Reactions
What always happens in every chemical reaction?
Energy Change
How does decreasing particle size affect the speed of a chemical reaction?
Increase it.
What does the pH scale measure?
Acidity (acid/alkali/neutral).
Which is the only metal that rusts?
Iron
What are the 3 states of matter?
Solid, liquid and gas
What can be seen when a chemical reaction takes place?
Colour change/solid formed/gas produced (any one).
Why does decreasing particle size affect the speed of a chemical reaction?
Increased surface area (for the chemicals to react).
Give the name of an everyday acid.
Vinegar/lemon juice etc.
Name 2 ways in which rusting can be sped up.
With acid or by adding salt.
What are the particles called that make up everything?
Atoms
Name an everyday chemical reaction.
Rusting/baking a cake/making toast/etc.
What is a catalyst?
Speeds up a chemical reaction and can be recovered at the end unchanged.
If an acid is diluted with water, what happen to the pH?
The pH rises towards pH 7.
What is galvanising?
Coating (the metal) with a layer of zinc.
How are the particles arranged in a gas?
Far apart
What is the name given to the chemical reaction when bubbles of gas are given off?
Effervescence
give an example of a very fast chemical reaction.
Explosion/bomb going off/rocket taking off/etc.
What is the name given to a chemical reaction when an acid reacts with an alkali?
Neutralisation.
What conditions must be present for corrosion to occur?
Oxygen (air) and water
What can be said about the movement of solid particles?
They only vibrate
What is the name given to a solid forming from two liquids?
Precipitation
If 2 g of a catalyst was added to a chemical reaction, how much would be left at the end of the reaction?
2 g.
If hydrochloric acid is reacted with sodium hydroxide, what are the names of the chemicals formed?
Sodium chloride (salt) and water.
Rust indicator is a chemical test to detect rusting. What is the colour change that is seen?
Yellow/green to blue
When water changes to steam, this is called ________?
Boiling