Chemical Analysis Flashcards
What is a pure substance?
A single element or compound, not mixed with any other substance.
Example: Water.
What can we use to identify if a substance is pure?
Check its melting and boiling points.
Pure substances always melt/boil at the same temperatures.
Why do pure and impure substances have different melting and boiling points?
Pure and impure substances will have different melting and boiling points.
What is a formulation?
A mixture of different substances that has been designed as a useful product.
How are formulations made?
By mixing the components in carefully measured quantities to ensure that the product has the required properties.
What are some examples of formulations?
Fuels, cleaning agents, paints, medicines, alloys, fertilisers, foods.
What is the test and result for hydrogen gas
Lit splint into top of test tube, lit splint goes out with a squeaky pop
What is the test and result for oxygen gas?
Glowing splint into test tube, relights the glowing splint (flame again)
What is the test and result for carbon dioxide gas
Bubble the co2 through limewater, goes from colourless to cloudy
What is the test and result for chlorine gas
Piece of damp litmus paper, bleaches the paper from blue litmus to bleached white paper
What is a precipitate
An insoluble solid formed when two liquids react
What can be used to identify positive metal ions
Reaction with sodium hydroxide
What is lime water? (Formula name)
Calcium hydroxide
