1. Demonstrate Understanding of Acids and Bases
Science 1.5 (AS90944)

2. Specific Learning Outcomes
Name some common acids and bases
Use litmus to identify an acid and describe the colour change
Define the terms
Element
Atomic number
Atomic mass /mass number
Isotope
Know names & symbols for first 20 elements
Describe, draw and label diagrams of atomic structure
Use atomic number and mass number to calculate the protons, neutrons and electrons
Describe the structure of the periodic table
Specific Learning Outcomes

3. Specific Learning Outcomes
Write electron configs. in diagrammatic and shorthand form
Use electron config. to identify its periodic group
Name and write formulae for common compounds
Describe how positive and negative ions are formed
Write ion formulae and identify protons, neutrons and electrons in ions
Name and write formula of a range of positive and negative ions
Name and write formulae for a range of ionic compounds
Write word and balanced symbol equations for a range of chemical reactions
Specific Learning Outcomes

4. Specific Learning Outcomes
Use collision theory to describe how chemical reactions occur
Understand what things affect the reaction rate and how
Name and write the formula for hydrochloric, sulfuric and nitric acids, metal oxides, metal hydroxides, metal carbonates and hydrogen carbonates
Use universal indicator to identify acids and bases
Use the pH scale to identify acids and bases
Describe and write balanced equations for a range of reactions including neutralisation, carbon dioxide formation and salt formation
Specific Learning Outcomes

5. Common acids and bases Acids: Bases: Taste sour Taste bitter
Corrode metals
Feel slippery
Turn litmus red
Turn litmus blue
Universal indicator is red to green
Are: hydroxides, oxides, carbonates, hydrogen carbonates
Universal indicator is green to blue
Substance
Formula
Colour in litmus
Acid or Base
Vinegar
CH3COOH
Baking soda
NaHCO3
Hydrochloric acid
HCl
Sodium hydroxide
NaOH
Sulfuric acid
H2SO4
Nitric acid
HNO3
Washing soda
Na2CO3
Red
Acid
Blue
Base
Red
Acid
Blue
Base
Red
Acid
Red
Acid
Blue
Base
Common acids and bases

6. Atoms are the smallest part of an element that can take part in a chemical reaction
They are made up of:
Protons (+ve charge)
Electrons (-ve charge)
Neutrons (no charge)
Protons and neutrons are found in a central nucleus and contribute most of the mass
Electrons spins rapidly around the outside
Atomic Structure

7. Atomic number and mass number
Atoms have two properties:
Atomic number – The number of protons (smaller)
Mass number – The number of protons plus the number of neutrons (larger)
Using the above for an example we can find the number of protons, neutrons and electrons in chlorine.
17 protons – the atomic number of the atom
18 neutrons – the mass number minus the atomic number
17 electrons – because the atom is neutral, the number of protons = number of electrons
Atomic number and mass number

8. The electrons (same as the protons and atomic number) can be represented diagrammatically or in shorthand form
Using the example from the slide before they would be as follows
or Cl 2, 8, 7
Electron Config.

9. Atomic structure Practice
Complete the table below
Element
Symbol
Atomic #
Atomic mass
# proton
# neutron
# electron
Electron config
Hydrogen H 1
 Oxygen O  8
 16 8 
2, 6
 Phosphorus  P 15
 31
 15
2, 8, 5 
 Sulfur  S
16  32
 2, 8, 6
 Boron  B  5
 11 5  6
 2, 3
 Calcium
 Ca
 20
 40 20
 2, 8, 8, 2
Element
Symbol
Atomic #
Atomic mass
# proton
# neutron
# electron
Electron config
Hydrogen H 1 8
2, 6 15 32 5 20
Atomic structure Practice

10. Isotopes An isotope is different forms of the same element
They are atoms with the SAME number of protons but DIFFERENT numbers of neutrons they therefore have:
Different mass numbers
Same atomic number
Same number of electrons
Same chemical reactions
Isotopes

11. The periodic table shows similarities, differences and relationships between elements
Arranged in rows according to their atomic number
Vertical columns = groups
all elements in the same group
have the same number of electrons in their outer shell
Have similar properties
Horizontal rows = periods
Elements in the same period have the same number of electron shells
As you go across a period 1 extra electron is added until the far noble gases on the right which have 8 (a full outer shell)
Metals are on the left and non-metals on the right
Periodic Table

12. Periodic Table

13. Atoms that have lost or gained electron in a chemical reactions are called IONS
Atoms will gain or lose electrons to fill their outer shell and become more stable
A positive ion (cation) will lose electrons leaving it with an overall positive charge
A negative ion (anion) will gain electrons leaving it with an overall negative charge
Eg Sodium (Na), atomic number 11, electron arrangement 2, 8, 1 will lose the one electron to have a full outer shell (the 2nd)
Chlorine (Cl) atomic number 17, electron arrangement 2, 8, 7 will gain 1 electron to have a full outer shell (the 3rd)
Ions and Ionic bonding

14. Atoms that do not lose or gain electrons are said to be unreactive (the noble gases)
Some ions are made up of more than 1 element eg:
Hydroxide OH-
Ammonium NH4+
Nitrate NO3-
Hydrogen carbonate HCO3-
Carbonate CO32-
Phosphate PO43-
Ions 2

15. Ions 3 Complete the table Element Electron Config Lose or gain ele
How many
Ion formed
Config of ion
Lithium
2, 1
Lose 1
Li+ 2
Hydrogen H+
Fluorine
2, 7
Gain F-
2, 8
Aluminium
2, 8, 3 3
Al3+
Sulfur
2, 8, 6
S2-
2, 8, 8
Potassium
2, 8, 8, 1 K+
Element
Electron Config
Lose or gain ele
How many
Ion formed
Config of ion
Lithium
2, 1
Lose 1
Li+ 2
Hydrogen
Fluorine
Aluminium
Sulfur
Potassium
Ions 3

16. Ions react together in chemical reactions to form compounds
The positive and negative charges need to balance each other out in order to make a stable compound
Eg:
Ionic Bonding

17. Ionic Table Sulfide +1 +2 +3 -1 -2 -3 H+ hydrogen Mg²+ magnesium A13++1 +2 +3 -1 -2 -3 H+
hydrogen
Mg²+
magnesium
A13+
aluminium
C1-
Chloride
O²-
oxide
N3-
nitride
Na+
sodium
Ca²+
calcium
Fe3+
iron (III)
OH-
hydroxide
CO3²-
carbonate
PO4-3
phosphate K+
potassium
Fe²+
iron (II)
NO3-
nitrate
SO4²-
Sulfate
 NH4+
Ammonium
Cu²+
copper (II)
HCO3-
bicarbonate
S²-
Sulfide
Zn²+
zinc
Pb²+
lead
Ionic Table

18. Rules for writing and naming ionic compounds
Write the positive ion first
Overall charges must be ‘0’
Use a subscript number to show the ration of ions in the compound to remove charges
Generally ‘ide’ indicates only 1 type of atom while ‘ate’ indicates an atom combined with oxygen – exception ??
When writing formulae with ions involving more than one atom, you must use brackets around the ion
Rules for writing and naming ionic compounds

19. You can tell if a chemical reaction has occurred by…
Observing changes in
Colour
Smell
Appearance
Temperature
Electrical conductivity
Noting differences in the physical properties of the reactants and products
Testing the chemical appearance of the reactants and products
A new product is made
Chemical Reactions

20. Chemical reactions can occur using different types of reactant. Eg.
Two different elements
Hydrogen gas and chlorine gas make hydrogen chloride
A compound and an element
Hydrochloric acid and magnesium makes magnesium chloride and hydrogen gas
Two different compounds
Copper sulfate and sodium hydroxide make copper hydroxide and sodium sulfate
A compound splits into 2 elements
Aluminium oxide turn into aluminium and oxygen
A compound splits into 2 compounds
Calcium carbonate makes calcium oxide and carbon dioxide
A compound splits into an element and a compound
Hydrogen peroxide makes water and oxygen
Chemical Reactions

21. A chemical equation is used to summarise what is happening in a chemical reaction
It has reactants on the left and products on the right
These can be written as word equations:
Sodium + sulfuric sodium sulfate + Hydroxide acid water
Or Formula equations (these should be balanced)
2NaOH + H2SO4 Na2SO4 + H2O
Chemical equations

22. Chemical Equations 2 Steps to follow to write a balanced equation
Write down the names of the reactants and products
Hydrogen + oxygen water
Write down the correct formula for the reactants and products
H2 + O2 H2O
Balance the equation by putting numbers in front of each reactant and product
2H2 + O2 2H2O
Chemical Equations 2

23. The particle theory state that all substances are made or particles – atoms, ions or molecules.
Chemical reactions take place when the particles of the reactant collide with one another with sufficient energy to react and form product particles
As the reactants turn into product, the rate of the reaction slows.
Eventually one or both of the reactants are all converted to product and the reaction stops
Collision Theory

24. Factors affecting Reaction rate
Rate of reaction

25. Reactions of Acids and bases
When ever an acid reacts it forms a salt plus other products
The name of the salt depends on the acid reacting
Hydrochloric acid ______ Chloride
Nitric acid ______ Nitrate
Sulfuric acid ______ Sulfate
Reactions of Acids and bases

26. Neutralisation This is the reaction of an acid and a base
It produces a product with a pH of 7 (neutral)
The general reaction is:
Acid + Base Salt + Water
Oxides and Hydroxides is also a neutralisation with the reaction being
Acid + Oxide Salt + Water
Acid + Hydroxide salt + water
Carbonates or hydrogen carbonates react with acids also but in these reactions Carbon dioxide is also produced
Acid + carbonate Salt + Water + Carbon dioxide
Acid + hydrogen carbonate salt + water +carbon dioxide
Neutralisation