Answer:- 
Explanations:- The solution we have is a buffer solution and we know that a buffer solution resists a change in its pH if a strong acid or base is added to it.
Here, the buffer solution we have is of a weak base and it's conjugate acid. So, a strong acid(nitric acid) is added to this buffer then it reacts with the base present in the buffer so that the acid could be neutralized. This is called buffer action.
The net ionic equation is written as:

Note that
is a strong acid and nitrate ion is the spectator ion so it is not included in the net ionic equation.
Answer: Mixtures you can separate are like cereal and milk. Hope that helps
Explanation: Filteration is required to separate a mixture.
So heterogeneous mixures (that contain substances with different particle sizes) can be separated with a filter.
Homogeneous mixtures are uniform in composition so they will not be able to be separated.
B) A chemical change because the nail reacts with water/oxygen to create rust (a type of oxide)
Answer: Phosphorus is insoluble in water, but soluble in carbon disulfide. Phosphorus burns spontaneously in air to its pentoxide.
Explanation: Hope this helped! :)