Trusted by millions of Kenyans
LoginRegister
Study resources on Kenyaplex

Get ready-made curriculum aligned revision materials

Exam papers, notes, holiday assignments and topical questions – all aligned to the Kenyan curriculum.

Browse exam papers
Or go directly to:
Class notes Holiday assignments Topical questions Other resources

Describe and experiment of making a simple cell

Describe and experiment of making a simple cell

Answers

Raphael
Experiment: making a simple cell

Procedure:
1. Take a piece of copper strip and zinc strip and clean thoroughly with emery paper.
2. Put the two strips in a beaker containing dilute sulphuric acid.
3. Observe what happens to the strips.
4. Connect the strips externally to a milliameter and a voltmeter.
simplecell11102018.jpg
Discussion:
Sulphuric acid is chemically written as, H2SO4 ----- 2H+ + SO42-
The electrons liberated by the acid move to the zinc electrode Zn ------ Zn2+ + 2e-
The hydrogen ions move to the copper strip 2H+ + 2e- ---- H2
Copper strip therefore becomes positively charged while the zinc becomes negatively charged electrode.

The accumulation of bubbles around the copper strip is called polarization. The bubbles formed around the zinc strip is the reaction of acid with zinc impurities and is called local action. Polarization produces insulation between the strip and the acid cutting off production of current eventually. This is known as the internal resistance of the cell. Local action eats away the zinc strip and a mercury coat is applied to prevent this (amalgamation). Polarization and local action are the main defects of simple cells.
raphael answered the question on October 11, 2018 at 07:20

Answer Attachments

Next: Read the following poem and answer the questions that follow.

Previous: Describe an experiment to charge and discharge a simple secondary cell

View more Physics Questions and Answers  |  Return to Questions Index

Exams With Marking Schemes

Related Questions