A student dipped a clean piece of magnesium ribbon in a beaker containing a colourless liquid labelled
solution D. A vigorous reaction took place and effervescence was observed. A colourless solution
remained in the beaker, he divided this resulting solution into 2 portions. To the first portion he added 3
drops of acidified Ba(NO3)2 and the solution remained colourless. To the second he added 3 drops of
lead(ll)nitrate solution and a white ppt was formed. (8mks)
i. Identify solution D
ii. Write a chemical equation for the reaction between magnesium ribbon and solution D
iii. Why was it important to clean the magnesium ribbon before using it
iv. Describe how one can test the gas produced
v. What inference did the student draw from test 1
vi. Write an ionic equation for the formation of the white precipitate
A green rocky solid suspected to contain basic copper(ll)carbonate was heated and the gas produced was dried
and passed over heated charcoal in combustion tube 1. The products from the combustion tube were passed
through agueous sodium hydroxide solution and then through combustion tube ll containing heated lead(ll)oxide.
A grey solid was observed after the experiment.
i. State the observation made when basic copper(ll)carbonate was heated.
ii. Write a chemical equation for the reaction between the gaseous product and the heated charcoal
iii. What type of reaction took place between lead(ll)oxide and the products from combustion tube l? explain
iv. What was the purpose of passing the products in combustion tube 1 through sodium hydroxide solution
v. Give two properties of the carbon (lv)oxide that make it suitable for use in fire extinguishers
vi. Explain why carbon(lv)oxide that make it suitable for use in fire extinguishers
vii. Explain why carbon(lv)oxide is preferred to water when putting off oil fire
Limestone is one of the raw materials in the solvay process. What is the role of limestone in this process
viii. Describe how sodium carbonate is manufactured in the solvay process.
solution D. A vigorous reaction took place and effervescence was observed. A colourless solution
remained in the beaker, he divided this resulting solution into 2 portions. To the first portion he added 3
drops of acidified Ba(NO3)2 and the solution remained colourless. To the second he added 3 drops of
lead(ll)nitrate solution and a white ppt was formed. (8mks)
i. Identify solution D
ii. Write a chemical equation for the reaction between magnesium ribbon and solution D
iii. Why was it important to clean the magnesium ribbon before using it
iv. Describe how one can test the gas produced
v. What inference did the student draw from test 1
vi. Write an ionic equation for the formation of the white precipitate
A green rocky solid suspected to contain basic copper(ll)carbonate was heated and the gas produced was dried
and passed over heated charcoal in combustion tube 1. The products from the combustion tube were passed
through agueous sodium hydroxide solution and then through combustion tube ll containing heated lead(ll)oxide.
A grey solid was observed after the experiment.
i. State the observation made when basic copper(ll)carbonate was heated.
ii. Write a chemical equation for the reaction between the gaseous product and the heated charcoal
iii. What type of reaction took place between lead(ll)oxide and the products from combustion tube l? explain
iv. What was the purpose of passing the products in combustion tube 1 through sodium hydroxide solution
v. Give two properties of the carbon (lv)oxide that make it suitable for use in fire extinguishers
vi. Explain why carbon(lv)oxide that make it suitable for use in fire extinguishers
vii. Explain why carbon(lv)oxide is preferred to water when putting off oil fire
Limestone is one of the raw materials in the solvay process. What is the role of limestone in this process
viii. Describe how sodium carbonate is manufactured in the solvay process.
