ELECTROLYSIS OF ZnI2
if you have done this experiment Please help me answer these questions as i missed the last half of my chem lab today.
1. What color change occurred when the wire is first heated.
-next question is...
What is the identity of the liberated metal?
2. what color change occurred when starch is added? what is the liberated substance (which was in solution before you added starch) to be?
1 second ago - 4 days left to answer.
To answer your questions about the electrolysis of ZnI2, let's break down the process and go through each question step by step.
1. Color change when the wire is first heated:
When the wire is first heated in the electrolysis of ZnI2, it will turn red or glow red. This is due to the heat causing the wire to emit energy in the visible light spectrum, which our eyes perceive as the color red.
2. Identity of the liberated metal:
In the electrolysis of ZnI2, the liberated metal is zinc (Zn). This can be determined by observing the products of the electrolysis reaction at the cathode. At the cathode, positively charged ions (cations) in the electrolyte solution gain electrons and are reduced. In the case of ZnI2 electrolysis, the zinc ions (Zn2+) at the cathode gain electrons to form elemental zinc metal.
3. Color change when starch is added and the liberated substance:
The addition of starch to the electrolysis of ZnI2 does not directly cause a color change. Starch is a white powdery substance that does not have a significant effect on color. However, starch can act as an indicator for the presence of iodine (I2), which may have been liberated during the electrolysis.
If iodine is present, it will react with the starch to form a dark blue or black complex called iodine-starch complex. Therefore, if the solution turns dark blue or black upon adding starch, it indicates the liberation of iodine, which before adding starch was in the form of iodide ions (I-) in the solution.
In summary:
1. The wire turns red when heated.
2. The liberated metal is zinc (Zn).
3. Starch does not cause a color change itself, but it can react with liberated iodine (if present) to form a dark blue or black complex. The liberated substance, before adding starch, would be iodide (I-) ions in solution.
For more accurate and specific answers to your questions, it is always best to refer to the lab procedure or consult your lab instructor, as they may provide additional details or variations specific to your experiment.