1. Introduction to Chemistry
S2 Chemistry
Introduction to Chemistry

2. Introduction to Chemistry
1.1 Reaction Rates
1.2 Chemical Formula (elements)
1.3 Chemical Formula (compounds)

3. 1.1 Reaction Rates Learning Intentions
To learn how to speed up a chemical reaction

4. Success Criteria
I can list the 4 methods a reaction can be made faster.
I can describe the effect of a catalyst and an enzyme on a reaction
I can do experiments to show how a reaction’s speed can be increased.
I can evaluate and explain graphs showing speeds of reactions.
I can explain everyday reactions and how to speed them up.

5. Particle Size Apparatus 0.5M hydrochloric acid chalk lumps
chalk powder
2 boiling tubes
test tube rack

6. Particle Size
Method
Two boiling tubes were ¼ filled with 0.5M hydrochloric acid.
4 lumps of chalk were put into one boiling tube
A similar quantity of chalk powder was put into the other boiling tube
Record your results

7. Particle Size
Results
Decreasing the particle size (making the bits smaller) increases the rate of reaction.

8. Temperature Apparatus glucose powder Benedict’s solution Metal beaker
Bunsen and bench mat
Tripod and gauze

9. Temperature
Method
Half fill the metal beaker with water. Heat it with a blue flame until it is boiling then switch off the bunsen.
¼ fill two test tubes with water. Put a spatula of glucose into each test tube.
Put 10 drops of Benedicts into each test tube
Place one of the test tubes into the hot water
Record your results.

10. Temperature
Results
Increasing the temperature increased the rate of the reaction.

11. Concentration
Method

12. Concentration
Results

13. Summary To speed up a chemical reaction you could -
Increase temperature
Increase concentration
Decrease particle size

14. Catalysts
A catalyst is a substance which increases the speed of a chemical reaction without itself being changed.

15. Enzymes
An enzyme is a biological catalyst

16. Enzymes An enzyme is a biological catalyst
Liver contains an enzyme which speeds up certain chemical reactions.

17. We are learning to write element formula

18. 1.2 Chemical Formula (elements)
Learning Intention
We are learning to write element formula

19. Success Criteria
I can write formula for elements

20. Chemical Formula (elements)
All elements are given a name and a symbol
eg name hydrogen
symbol H

21. Chemical Formula (elements)
Some elements have symbols that contain two or more letters
eg name magnesium
symbol Mg

22. Chemical Formula (elements)
Some elements have symbols that contain two or more letters
eg name magnesium
symbol Mg
The first letter only must be a capital letter

23. 1.3 Chemical Formula (compounds)
Leanning Intention
We are learning to write chemical formula

24. Success Criteria
I can write chemical formula for compounds containing the prefixes mono, di, tri, tetra
I can write chemical formula for compounds with 2 elements
I can write chemical formula for compounds with more than 2 elements
I can write chemical formula for compounds containing roman numerals

25. Naming Compounds
A compound is formed when 2 or more different elements chemically join together.

26. Naming Compounds -ide only two elements forming the compound
-ate two elements plus oxygen
-ite two elements plus oxygen

27. Naming Compounds Elements Present Name of Compound Magnesium oxide
Silver chloride
Lead sulphur
Iron sulphur oxygen
Sodium nitrate
Iron oxygen
Copper carbonate

28. Sodium nitrogen oxygen
Naming Compounds
Elements Present
Name of Compound
Magnesium oxygen
Magnesium oxide
Silver chlorine
Silver chloride
Lead sulphur
Lead sulphide
Iron sulphur oxygen
Iron sulphate
Sodium nitrogen oxygen
Sodium nitrate
Iron oxygen
Iron oxide
Copper carbon oxygen
Copper carbonate

29. Valency or Combining Power
The valency or combining power is the number of connections an atom can have with another atom.

30. Linking Atoms
Group 1 2
Transition
metals 3 4 5 6 7 8
Valency
mainly

31. Using the Valency
If we know the valencies of the atoms combining then we can work out the formula of the compound they form.
Eg water

32. Using the Valency
Symbol H O

33. Using the Valency
Symbol H O
Valency

34. Using the Valency
Symbol H O
Valency H O

35. Using the Valency
Symbol H O
Valency H O H

36. Using the Valency
Symbol H O
Valency H O H

37. Using the Valency Symbol H O Valency 1 2 H2O H O H
No arms can be left unattached

38. Example – carbon hydride
Symbol C H

39. Using the Valency
Symbol C H
Valency

40. Using the Valency
Symbol C H
Valency C H

41. Using the Valency
Symbol C H
Valency H
CH4
methane H C H H

42. Writing Formula Calcium oxide Magnesium sulphide Calcium carbide
Aluminium phosphide
Calcium bromide

43. Writing Formula Calcium oxide CaO Magnesium sulphide MgS
Calcium carbide Ca2C
Aluminium phosphide AlP
Calcium bromide CaBr2

44. Writing Formula In certain compounds the name tell you the formula
mono = 1
di = 2
tri = 3
Tetra = 4
Eg nitrogen dioxide = NO2

45. Writing Formula Dinitrogen tetraoxide Hydrogen oxide Carbon hydride
Nitrogen fluoride
Magnesium carbide
Potassium nitride

46. Writing Formula Dinitrogen tetraoxide N2O4 Hydrogen oxide H2O
Carbon hydride CH4
Nitrogen fluoride NF3
Magnesium carbide Mg2C
Potassium nitride K3N

47. Formula with groups Groups of atoms can be given a valency as well Eg
the sulphate ion has a valency of 2
SO4

48. Formula with groups
nitrate
NO3
phosphate
PO4
hydroxide OH

49. Formula Roman Numerals
Roman numerals in a formula give the valency of the transition metal Eg iron (II) oxide

50. Formula Roman Numerals
Roman numerals in a formula give the valency of the transition metal Eg iron (II) oxide O Fe

51. Formula Roman Numerals
Roman numerals in a formula give the valency of the transition metal Eg iron (II) oxide
FeO O Fe