February 2025

Inhaled vs Exhaled air experiment: Method 1

By |2025-02-12T09:37:32+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Image credit vimeo.com Image credit vimeo.com ZIMSEC O Level Combined Science Notes: Inhaled vs Exhaled air experiment: Method 1

Aim: Comparing the inhaled and exhaled air.

Materials: large transparent container (e.g. bell jar), candle, tin lid, water, large basin, rubber tubing, ruler.

Method

exhaled_inhaled_air-min

  1. Place the large […]
Read More
Comments Off on Inhaled vs Exhaled air experiment: Method 1

Asexual reproduction

By |2025-02-12T09:34:33+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

A bud on a sugarcane cutting. Image credit 10degreesabove.com A bud on a sugarcane cutting. Image credit 10degreesabove.com ZIMSEC O Level Combined Science Notes: Reproduction in plants: Asexual reproduction/ Vegetative reproduction  

  • Is also known as asexual reproduction
  • This takes place when plants reproduce without producing seeds
  • Such plants have modified stems, roots or […]
Read More
Comments Off on Asexual reproduction

Variation

By |2025-02-12T08:59:05+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Variation in chillies. Image credit chilipapryczka.pl Variation in chillies. Image credit chilipapryczka.pl ZIMSEC O Level Combined Science Notes: Variation

  • The living world has many thousands of different types of plants and animals
  • For example lions are different from hyenas which in turn are different from say goats
  • In plants the Msasa trees are […]
Read More
Comments Off on Variation

Experiment: to show that solids change shape when they melt

By |2025-02-12T09:11:07+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Melting wax takes up the shape of the container. Image credit about.com Melting wax takes up the shape of the container. Image credit about.com ZIMSEC O Level Combined Science Notes: An  experiment to show that solids change shape when they melt

Materials: tin lid/evapouration dish, burner, burner stand, candle wax

Method

  1. place […]
Read More
Comments Off on Experiment: to show that solids change shape when they melt

Chemical Reactions

By |2025-02-12T09:19:25+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Chemical Reactions

Introduction to reactions

  • A compound is formed when a chemical reaction takes place
  • Chemical change takes place to form the compound
  • Word equations can be used as a short hand way to show what has happened
  • An example of a chemical equation is:
  • \text{iron + sulpher}\rightarrow \text{iron sulphide}
  • As already […]
Read More
Comments Off on Chemical Reactions

Experiment: Reducing Iron oxide using aluminium

By |2025-02-12T08:56:02+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Experiment: Reducing Iron oxide using aluminium

Aim: To remove oxygen from iron oxide using aluminum

Materials: sand, tin can, safety screen, magnesium ribbon and magnesium powder, wooden splint, aluminum powder, dry iron oxide, barium preoxide

Reducing iron oxide using aluminum oxide Reducing iron oxide using aluminum oxide

Method

  1. Fill the tin […]
Read More
Comments Off on Experiment: Reducing Iron oxide using aluminium

Experiment: Investigating the effects of concentration on marble chips

By |2025-02-12T09:15:36+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Concentration varies directly with the rate of reaction Concentration varies directly with the rate of reaction ZIMSEC O Level Combined Science Notes: Experiment: Investigating the effects of concentration on marble chips

Aim: To investigate the effect of concentration on the reaction between marble chips and hydrochloric acid

Materials : conical flask/glass jam jars, measuring cylinder, […]

Read More
Comments Off on Experiment: Investigating the effects of concentration on marble chips

Experiment: Separating copper from its oxides

By |2025-02-12T09:30:43+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Experiment: Separating copper from its oxides

Aim: To separate copper from its oxide ores

Materials: copper oxide, iron nail, dilute sulphuric acid, filter funnel, 2 beakers, stirring rod, filter paper, burner

Extracting copper from copper oxide Extracting copper from copper oxide

Method

  1. Place a small amount of copper oxide in a […]
Read More
Comments Off on Experiment: Separating copper from its oxides

The Manufacture of sulphuric acid

By |2025-02-12T08:56:03+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

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

  • Sulphuric acid is produced using the Contact process
  • In Zimbabwe there is a sulphuric acid production plant at Zimphos in Harare
  • Sulpher or iron pyrites (iron sulphide) is roasted to form sulphur dioxide
  • The word equation for roasting iron pyrites is:
  • \text{iron sulphide+oxygen}\rightarrow\text{iron oxide+sulpher dioxide}
  • The word […]
Read More
Comments Off on The Manufacture of sulphuric acid
Toggle Sliding Bar Area
Go to Top