February 2025

Experiment:Making coke and collecting the resulting gases

By |2025-02-12T09:05:22+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Making coke Making coke ZIMSEC O Level Combined Science Notes: Experiment:Making coke and collecting the resulting gases

Aim: To make coke using coal and collect the gas and liquid by-products

Materials: crushed coal, test tubes, glass tubing, splints, lead ethanoate solution, filter paper, red and blue litmus paper, sodium hydroxide solution, beaker, water, trough, […]

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Biogas as a source of energy

By |2025-02-12T09:06:04+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Biogas as a source of energy

  • Biogas is the gas that is obtained from fermenting manure and other organic waste
  • It is a mixture of methane, carbon dioxide and hydrogen sulphide
  • Cattle manure is commonly used as a waste to feed biogas plants
  • Small plants have been built in some parts of Zimbabwe

    • […]

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Ethanol as a source of energy

By |2025-02-12T09:07:30+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Ethanol as a source of energy

  • Ethanol is also known as alcohol
  • It is made by fermenting plants with a high sugar content
  • Sugar cane is commonly used to make ethanol in Zimbabwe
  • The plant is grown in Zimbabwe’s Lowveld
  • Water from Mutirikwe and Bangala Dams is used to irrigate the crop
  • Biomas is […]
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Experiment making ethanol

By |2025-02-12T09:08:16+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Fermentation of glucose Fermentation of glucose ZIMSEC O Level Combined Science Notes: Experiment: making ethanol

Aim: To make ethanol by fermenting glucose

Materials: conical flask/plastic bottle, cork, glass/rubber tube,lime water, 5% glucose solution, yeast, mealie meal

Method

  1. Add about 50cm3 of the 5% glucose solution into the flask
  2. Add a spatula of yeast/mix mealie meal with water […]
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Experiment: Distillation of alcohol

By |2025-02-12T09:08:51+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Distillation of alcohol. Image credit bbc.co,uk Distillation of alcohol. Image credit bbc.co,uk ZIMSEC O Level Combined Science Notes: Experiment: The distillation of ethanol

Aim: To concentrate alcohol using the distillation process

Materials: thermometer, clamp stands, rubber bungs, round bottomed flask, fractionating column. condenser with rubber tubing, watch-glass or tin lid, porcelain chips or clean dry sand

    […]
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Experiment: Determining the best conditions for the production of ethanol

By |2025-02-12T09:09:40+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Fermentation of glucose Fermentation of glucose ZIMSEC O Level Combined Science Notes: Experiment: Determining the best conditions for the production of ethanol

Aim: To determine the best conditions for ethanol production

Materials: 5% glucose solution, 20% glucose solution, yeast, sodium hydroxide solution, mealie meal, dilute hydrochloric acid, thermometer, conical flask, cork, glass tube, test tube, […]

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Experiment: Demonstrating that carbon dioxide extinguishes a burning flame

By |2025-02-12T09:10:46+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Carbon dioxide extinguishes flames Carbon dioxide extinguishes flames ZIMSEC O Level Combined Science Notes: Experiment: Demonstrating that carbon dioxide extinguishes a burning flame

Aim: to show that carbon dioxide extinguishes a flame

Materials:  3 different sized candles, vinegar, baking soda, beaker or plastic bottle, shallow dish

Method

  1. Place the 3 pieces of candle in a […]
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Fuel efficiency

By |2025-02-12T09:11:15+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Fuel efficiency

  • Fuel efficiency measures the amount of energy that can be obtained from a given quantity of fuel
  • It is often useful to know which fuel gives the most energy(heat) per given unit
  • In a laboratory fuel efficiency can be determined by measuring the temperature rise of water when it is […]
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Experiment:investigating fuel efficiency

By |2025-02-12T09:11:59+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Testing fuel to determine its energy content Testing fuel to determine its energy content ZIMSEC O Level Combined Science Notes: Experiment:investigating fuel efficiency

Aim: To determine the amount of heat liberated when different liquid fuels burn

Materials:  2 spirit burners, wooden block, clamp and stand, meths, paraffin, thermometer, draught shields, clamp, beaker, water, tripod […]

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Fuel Engines

By |2025-02-12T09:12:54+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Most cars use fuel engine. Image credit ecurrent.fit.edu/blog/ Most cars use fuel engine. Image credit ecurrent.fit.edu/blog/ ZIMSEC O Level Combined Science Notes: Fuel Engines

  • A machine is a device that changes energy from one form to another
  • When the energy used by the machine is chemical energy the machine is called […]
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