Answer:
Thus there was no accumulation of ions on the nails, as the dissolved gases were already removed, hence no rust formation. In test tube C, a chemical was added to absorb the water vapour. We know that rust formation takes place when a metal is exposed to water vapour.
Explanation:i hope u have a wonderful night and stays safe
Answer:
I think it both physical & chemical change :')
Answer:

Explanation:
Hello!
In this case, since the standard enthalpy change for a chemical reaction is stood for the enthalpy of reaction, for the given reaction:

We set up the enthalpy of reaction considering the enthalpy of formation of each species in the reaction at the specified phase and the stoichiometric coefficient:

In such a way, by using the NIST database, we find that:

Thus, we plug in the enthalpies of formation to obtain:

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