ch.10.elements, compounds and mixtures
TRANSCRIPT
Elements, compounds and mixtures
Chapter 10(Chemistry)Part 1
Pure Substances• A sample of matter that has definite
chemical and physical properties.
Elements Atoms
CompoundsMolecules
Elements• pure substance that cannot be separated into
simpler substance by physical or chemical means.
Mixtures• A combination of two or more pure substances that
are not chemically combined.• substances held together by physical forces, not
chemical • No chemical change takes place • Each item retains its properties
in the mixture • They can be separated physically
Chem4kids.com
CompoundsPure substance composed of two or
more different elements joined by chemical bonds.
– Made of elements in a specific ratio that is always the same– Has a chemical formula– Can only be separated by chemical means, not physically
H2O
CO2
NaCl
Can you identify the following?
You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture.
Review:• An element contains just one type of atom. • A compound contains two or more different atoms
joined together. • A mixture contains two or more different substances
that are only physically joined together, not chemically.– A mixture can contain both elements and compounds.
Element, Compound, or Mixture?Rocks
Element, Compound, or Mixture?Rocks
Element, Compound, or Mixture?Copper
Element, Compound, or Mixture?Copper
Cu
Element, Compound, or Mixture?Jelly Beans
Element, Compound, or Mixture?Jelly Beans
Element, Compound, or Mixture?Table Sugar
Element, Compound, or Mixture?Table Sugar
C 12H 22O 11
Element, Compound, or Mixture?Diamond
Element, Compound, or Mixture?DiamondC
Element, Compound, or Mixture?Tea
Element, Compound, or Mixture?Tea
Element, Compound, or Mixture?Salt
Element, Compound, or Mixture?SaltNaCl
Element, Compound, or Mixture?Neon Gas
Element, Compound, or Mixture?Neon GasNe
Element, Compound, or Mixture?Salad
Element, Compound, or Mixture?Salad
Element, Compound, or Mixture?Pure Water
Element, Compound, or Mixture?Pure WaterH 2O
Chemical reactions and equations.- Chemists use equations to describe a chemical reaction.- The equations save time and space.- The simplest equations are word equations.
- Substances that take part in a reaction are called the reactants.- The substances formed as a result of the chemical reaction are called the
products.
- In an equation the reactants are written on the left-hand side of the equation and the products are written on the right-hand side.
- If there are two or more reactants or products in the equation they are linked together by (+) sign.
Chemical names- Chemists use equations to describe a chemical reaction.- The equations save time and space.- The simplest equations are word equations.
How are compounds named? Prefix or suffix
1st part Name of the1st elementEx. Carbon Iron Sodium
2nd part Name of 2nd element
If 2nd element is not joined to other elements Suffix -ide is usedEx. Iron + Sulphur Iron sulfide Sodium + Chlorine Sodium chloride
If the 2nd element is more that one atom Prefix di- (two) tri- (three)Ex. Carbon dioxide Sulphur dioxide
If 2 elements are joined to the 1st element 2nd name is a mixture of the 2 elementsEx. Sodium Hydroxide
If the 2nd elements is joined to oxygen atoms Suffix -ate is usedEx. Calcium carbonate Ferrous sulphate
Compound Description and uses
Calcium Oxide(Quicklime)
A white solid used to produce limelight
Carbon dioxide A colourless gas produced in respiration
Copper oxide A black pigment used to colour pottery
Sulphur dioxide A colourless gas produced when fossil fuels are burnt
Potassium hydroxide - A colourless solid used in soap making- Makes an alkaline solution used in laboratories
Calcium hydroxide - A white solid used in the treatment of sewage and drinking water.- Used to make limewater for laboratory tests
Sodium Hydroxide - A colourless liquid used in soap making- Makes an alkaline solution used in laboratories
Sodium chloride A white crystalline solid also known as common salt
Compound Description and uses
Potassium chloride A white crystalline solid used in making fertiliser
Calcium chloride - A white solid which absorbs water vapour from the air.- Used to keep materials dry.
Calcium sulfate - White solid- Used to make plaster of Paris
Copper sulphate Can form a white powder or bright blue crystals
Calcium carbonate - A white solid- A component of snail shells and egg shells
present in large amounts in limestone.
Copper carbonate A blue green solid which can form the mineral called malachite