7 - CHEMISTRY - PURE AND INPURE SUBSTANCES (C2) Flashcards
(18 cards)
What are elements?
Materials that only contain one type of atom.
What is a compound?
Material that contains more than one type of atom chemically bonded together
What does a pure substance contain?
Only atoms or molecules of that substance.
What does a mixture/impure substance contain?
They contain two or more different substances that are not chemically bonded together.
What are impurities?
They are small amounts of other substances in a pure substance
What can impurities change?
They can change the physical properties of a pure substance. E.g the melting point and the boiling point
What are impurities?
They are small amounts of other substances in a pure substance
What are metal alloys an example of?
They are an example of an impure substance. A metal is given different properties by mixing it with another substance
How do different substances melt/boil?
They melt and boil at different temperatures
A: What do substances do to get from a liquid to a gas? B: What do substances do to get from a solid to a liquid?
A: Boil B: Melt
What is Solute?
The solid that is being dissolved.
What is a solvent?
The liquid the solute is being dissolved in
What is the solution?
The liquid that is formed when the solute has dissolved in the solvent
What does concentration tell us?
How much solute is dissolved in the solvent and is measured in g/dm3
What is the mass of solution formula?
Mass of the solute + Mass of the solvent
What is solubility?
How much solute will dissolve in a solvent to make a saturated solution (when no more can dissolve)
What is the saturation point?
Saturation point is reached when no more solute can be dissolved in the solvent
What is solubility affected by?
The temperature of the solvent e.g hot water has a higher solubility than cold water. More salt can be dissolved in hot water than in cold water
