Double replacement reactions- Cu(NO3)2 + 2NaOH ----> Cu(OH)2 + 2NaNO3 and Part C- Cu(OH)2 ----> CuO + H2O

Cu(NO3)2 + 2NaOH ----> Cu(OH)2 + 2NaNO3


This is the blue jelly like cupric nitrate solution
(Double replacement reaction)

The driving force is the formation of a solid.
Part C- Cu(OH)2 ----> CuO + H2O


It is changing into black cupric oxide
(Double replacement reaction)

The driving force is the formation of a solid and the formation of H2O