Please help meee! Chemistry!

What does a particular point on a line of a phase diagram represent? o a. the maximum temperature a substance can exist at without bonds breaking b. the pressure created by the kinetic energy of molecules at a particular temperature c. the melting point or boiling point of a substance at a specific pressure d. the conditions in which temperature and pressure have equal effects on a substance

If 1.8 l of water is added to 2.5l of a 7.0 m koh solution, what is the molarity of the new solution

Write a balanced equation showing the formation of copper (ii) nitrite from its elements