basic concepts on chemistry

1. Chemistry Revision Form 5 on topics: consumer, rate of reaction, carbon compound and thermo chemistry

4. d)Compare and contrast the cleansing action of soap and detergents animal plant Property Soap Detergent 1 sources Made from ……………… or ……………… Made from petroleum fractions

5. Alkyl group Property Soap Detergent 2 Molecular structure R – COO – Na + Where R is …………… R SO 3 – or

6. SCUM Property Soap Detergent 3 Effectiveness in hard water Forms ………………… with hard water Does not form scum with hard water

7. INSOLUBLE FATTY ACID Property Soap Detergent 4 Effectiveness in acidic water Forms …………… . with acidic water Does not form precipitate with acidic water

8. MORE Property Soap Detergent 5 Cleaning power Less powerful …………… powerful

9. POLLUTION Property Soap Detergent 6 Effect to the environment Biodegradable and do not cause any …………… Some detergents are non biodegradable and kill aquatic lives

11. Food additives DYES PRESERVATIVES FLAVOURING AGENTS ANTI OXIDANTS STABILIZERS AND THICKENING

12. TYPES OF FOOD ADDITIVES AND EXAMPLES

13. DYES PRESER VATIVES EXAMPLES TYPE 1) AZO COMPOUNDS 2) SODIUM NITRITE, SODIUM BENZOATE

14. FLAVOURING AGENTS ANTI OXIDANTS STABILIZERS & THICKENING AGENTS EXAMPLES TYPE 3) MONO SODIUM GLUTAMATE (MSG) 4) ASCORBIC ACID (VITAMIN C) 5) ACACIA GUM

15. TRADITIONAL MEDICINES

21. REVISION QUESTIONS

23. SAPONIFICATION ESTER TO PRECIPITATE SOAP PRODUCED

24. POTASSIUM HYDROXIDE

25. Water that contains Ca 2+ or Mg 2+ Soap react with Ca 2+ or Mg 2+ to form scum Detergent does not form scum in hard water.

26. Inhibit growth of microorganisms Antioxidants

27. burning sensations in the back, neck, chest; paralysis; numbness in the same areas; tingling or warmth in the face, arms or back; nausea; facial tightness; rapid heartbeat; chest pains, asthma attacks; drowsiness or cravings for other foods.

33. a ) Graph 9 shows the results of Experiment I and Experiment II to investigate the factor of catalyst in the reaction of zinc and hydrochloric acid. Volume of hydrogen gas (cm 3 ) Time(s) Experiment II Experiment I

40. b) Table 10 shows the molecular formula and the heat of combustion for propanol and butanol. Based on the information in Table 10, compare the heat of combustion between propanol and butanol. Explain why there is a difference in the values of the heat of combustion between propanol and butanol. [3 marks] Alcohol Molecular Formula Heat of combustion/ kJ mol -1 Propanol C 3 H 7 OH -2100 Butanol C 4 H 9 OH -2877

42. 5) Carbon compound Diagram shows the structural formula of two organic compounds K and L.

43. Compound K Compound L Compound K and L belong to two different homologous series.

44. ( a ) Write the general formula for the homologous series of compound K. C n H 2n+1 COOH ( b ) Name compound L. methyl propanoate

46. 6) Thermo chemistry example of paper 3 Plan a laboratory experiment to investigate the relationship between the molar mass of alcohols on the heat of combustion of alcohols. Your planning should include the following:

47. (a) Statement of problems Does an alcohol with a higher molar mass have a higher heat of combustion of alcohols? What is the relationship between the molar mass of alcohols and the heat of combustion of alcohols?

48. (b) All the variables Manipulated : variable Responding : Variable Constant : Variables Different types of Alcohols Heat of combustion volume of water, copper can

49. (c) Statement of hypothesis The higher the molar mass of alcohol, The higher the heat of combustion of alcohol

50. (d) List of substances and apparatus Substances : Methanol, ethanol, propan-1-ol, and butan-1-ol, water Apparatus : Copper can, measuring cylinder, Thermometer, spirit lamp, Bunsen burner, Tripod stand, wooden block, Wind shield, electronic balance

52. 6.Light up the wick of the lamp immediately 7.Stir the water continuously using a thermometer while observing the increase in temperature 8.Once the temperature has increased to 30 o C, put out the flame immediately 9.Record the highest temperature of water

53. 10.Weigh the spirit lamp with methanol again 11.Repeat step 1-10 by using ethanol, propan-1-ol, and butan-1-ol to replace methanol

54. (f) Tabulation of data Type of Alcohols Methanol Ethanol Initial temp of water ( o C) Highest temp of water( o C) Mass of spirit lamp before combustion(g) Mass of spirit lamp after combustion (g)

55. (f) Tabulation of data Type of Alcohols propanol butanol Initial temp of water ( o C) Highest temp of water( o C) Mass of spirit lamp before combustion(g) Mass of spirit lamp after combustion (g)