Question

The figure below shows the features of a dry cell (lenclanche). Use the information in the figure to answer the following questions.

1. Name the parts
2. Explain the purpose of B
3. State 2 defects of a dry cell and give their remedies

Answer 1

1.     
   • A - Seal and insulator 
   • B – Zinc case  
   • C – Mixture of carbon and manganese (IV) oxide    
   • D – Carbon rod 
2. Zinc case acts as a negative electrode
3.    
   1. Polarisation
      Remedy – Adding a depolarizer e.g potassium dichromate
   2. Local action
      Remedy – By amalgamation
      Accept – use of pure zinc or coating zinc with mercury