Question

What do you think would happen if you connected the pencil lead connected to the negative post after being in the copper nitrate solution to the positive post of the battery? explain why you think there would or would not be an observable change.

Answer 1

If you connected the pencil lead connected to the negative post after being in the copper nitrate solution to the positive post of the battery, it would result into flow of electrons.
Let us discuss why.

The pencil lead is made up of graphite which is a conductor of electricity due to presence of free electrons in it.
Whereas copper nitrate solution has copper ions which are the carriers of current.
Therefore, when the connection will be complete, the electrons will flow towards copper nitrate solution (positive electrode potential of 0.34V) which will result into deposition of copper metal on the surface or electrode.

No, a observable change will not recorded by the deposition of copper.
Because there is one drawback that there is no salt bridge like material which will balance the electronic charge hence the electrons cannot flow for a longer period of time.
Within few seconds the movement of electrons will stop and no deposition will be observed to the naked eye.

Overall, the reaction will occur but for few moments only. Thereafter, it will stop.

Good thoughtful question
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