February 2025

Differences between reduction and oxidation

By |2025-02-12T08:57:47+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Differences between reduction and oxidation

  • There are differences between oxidation and reduction
  • The table below shows the differences between oxidation and reduction:
  • Often reduction and oxidation occur in conjunction
  • That is at the same time and during the same reaction
  • For example:
  • \text{ammonia+oxygen}\rightarrow\text{water+nitrogen dioxide}
  • Nitrogen gains oxygen and losses hydrogen […]
Read More
Comments Off on Differences between reduction and oxidation

Experiment: The effects of a catalyst on the rate of a reaction

By |2025-02-12T09:17:07+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Copper (II) can be used as a catalyst. Image credit chemistry-reference.com Copper (II) can be used as a catalyst. Image credit chemistry-reference.com ZIMSEC O Level Combined Science Notes: Experiment: The effects of a catalyst on the rate of a reaction

Aim: To investigate the effects of a catalyst on a reaction using […]

Read More
Comments Off on Experiment: The effects of a catalyst on the rate of a reaction

Galvinasing iron

By |2025-02-12T09:31:31+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Corrugated iron sheets are galvanised. Image credit alibaba.com Corrugated iron sheets are galvanised. Image credit alibaba.com ZIMSEC O Level Combined Science Notes: Galvinasing iron

  • Galvanising is one of the methods used to prevent iron from rusting
  • Iron and steel can be coated with zinc
  • Zinc is a fairly more reactive metal

    • […]

Read More
Comments Off on Galvinasing iron

The production of Nitric acid

By |2025-02-12T08:58:32+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: The production of Nitric acid

  • Some of the ammonia produced using the Haber process is used in the production of nitric acid
  • The first stage in the process of making nitric acid is the oxidation of ammonia
  • To form nitric acid
  • \text{ammonia + oxygen} \rightarrow\text{nitric oxide+ water+heat}
  • This an exothermic reaction

    • […]

Read More
Comments Off on The production of Nitric acid

The Petrol engine

By |2025-02-12T09:13:38+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Four Stroke Petrol Engine. Image credit petrolheadkenya.com Four Stroke Petrol Engine. Image credit petrolheadkenya.com ZIMSEC O Level Combined Science Notes: The Petrol engine

  • Four strokes are involved in the operation of most petrol engines
  • They are thus known as four-stroke engines
  • The first stroke is known as the inlet stroke
  • During the […]
Read More
Comments Off on The Petrol engine

Experiment: Determining the resistance of resistors in parallel and in series

By |2025-02-12T09:29:49+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Resistors in series Resistors in series ZIMSEC O Level Combined Science Notes: Experiment: Determining the resistance of resistors in parallel and in series

Aim: To determine the combined resistance of resistors in series and in parallel

Materials: 4 cells, 2 bulbs/2 resistors, switch, ammeter, voltmeter, leads with crocodile clips

Method Resistors in [...] </p srcset=

Read More
Comments Off on Experiment: Determining the resistance of resistors in parallel and in series

Experiment: Generating electricity

By |2025-02-12T09:44:30+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

A dynamo. Image credit wikihow.com A dynamo. Image credit wikihow.com ZIMSEC O Level Combined Science Notes: Experiment: Generating electricity

Aim: To generate electric current

Materials: dynamo, lamp bulb, copper wires, crank or a set of pulleys and weights to turn dynamo, rubber band

Method

  1. Set up the apparatus with the dynamo on a table, the rubber […]
Read More
Comments Off on Experiment: Generating electricity

Testing the strength of various beams

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

Testing the strength of beams Testing the strength of beams ZIMSEC O Level Combined Science Notes: Experiment: Testing the strength of various beams

Aim: To make different shaped beams and test their strength

Materials:  thin pieces of poplar wood, sharp knife, weights, 2 clamps, 2 bricks

  1. Cut beams about 20cm long with different cross-sectional […]
Read More
Comments Off on Testing the strength of various beams

Experiment: Comparing the strength of natural timber and other construction materials

By |2025-02-12T09:25:11+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Comparing the strength of various materials Comparing the strength of various materials ZIMSEC O Level Combined Science Notes: Experiment: Comparing the strength of natural timber and other construction materials

Aim: To compare the strength of some natural timbers and other materials

Materials: Plywood, hard wood cut across the grain, soft wood cut along the grain, […]

Read More
Comments Off on Experiment: Comparing the strength of natural timber and other construction materials

Experiment:Lifting weights using pulleys

By |2025-02-12T09:43:02+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Testing pulleys using a test meter Testing pulleys using a test meter ZIMSEC O Level Combined Science Notes: Experiment:Lifting weights using pulleys

Aim: To use pulleys to lift loads

Materials:  4 single pulleys, string, 1kg mass/a tin filled with sand, spring balance, clamp stand, meter rule

Method

  1. Set up a fixed pulley as shown above

    2. […]

Read More
Comments Off on Experiment:Lifting weights using pulleys
Toggle Sliding Bar Area
Go to Top