Table of Contents
- 1 What happens when zinc iodide is Electrolysed?
- 2 What did you observe in the chemical reaction between iodine and zinc?
- 3 What is observed when molten zinc chloride undergoes electrolysis?
- 4 What is observed at each electrode when molten lead II bromide is electrolysed using platinum electrodes?
- 5 When fused lead bromide is Electrolysed we observe?
- 6 What is seen during electrolysis?
What happens when zinc iodide is Electrolysed?
P4 Electrolysis of an aqueous solution of zinc iodide. The solution close to the electrode connected to the positive pole turns brown. The brown solution sinks to the ground. When a voltage is applied, the positively charged zinc ions move to the electrode connected to the negative pole, the cathode.
What did you observe in the chemical reaction between iodine and zinc?
The reaction of zinc metal with iodine shows direct combination, decomposition, recrystallization of sublimed I2, and electrolysis. Mixture of Zn + I2 before water is added. Iodine vapor is produced when water is added. When power is connected, Zn and I2 crystals are formed.
What would you observe at the positive electrode?
Negatively charged chloride ions move to the positive electrode. Here, they lose electrons to form chlorine atoms. The atoms join up in pairs to form Cl 2 molecules, so chlorine gas is formed at the positive electrode.
Which effect can be observed during electrolysis?
Answer: Bubbles of gas may be formed at electrodes. Deposits of metal may be seen on electrodes. Change of colour of solution may occur!!
What is observed when molten zinc chloride undergoes electrolysis?
the metal is formed at the negative electrode because that is where the positive metal ions are attracted….Electrolysis of molten salts.
| Compound | Anode (positive) | Cathode (negative) |
|---|---|---|
| Zinc chloride | Chlorine | Zinc |
| Aluminium oxide | Oxygen | Aluminium |
What is observed at each electrode when molten lead II bromide is electrolysed using platinum electrodes?
Answer: Pb2+(l) + 2e– ==> Pb(l) This is a reduction reaction because the lead ions gain electrons. The negative bromide ions are attracted to the positive anode electrode and discharged to form bromine vapour.
What did you observe during the reaction of zinc iodide which reactant was a limiting reactant?
Notice that you have more moles of zinc metal than moles of iodine, which means that iodine will act as a limiting reagent, i.e. it will be completely consumed before all the moles of zinc get a chance to react.
How did you know that the reaction between zinc and the iodine had gone to completion?
When all the iodine has dissolved, slowly add the zinc powder using a spatula and stir the mixture with the thermometer. The temperature should rise, indicating an exothermic reaction. When the reaction is finished, the colour of the iodine should have faded and excess zinc will be left.
When fused lead bromide is Electrolysed we observe?
It is liberated at the anode. So reddish-brown fumes are deposited at the anode. Now this bromine atom combines to form a bromine molecule. Therefore a silver-grey deposit at the cathode and brown fumes at the anode are observed.
What is seen during electrolysis?
Positively charged ions move to the negative electrode during electrolysis. Negatively charged ions move to the positive electrode during electrolysis. They lose electrons and are oxidised . The substance that is broken down is called the electrolyte.
What do you understand by electrolysis?
electrolysis, process by which electric current is passed through a substance to effect a chemical change. The chemical change is one in which the substance loses or gains an electron (oxidation or reduction).