Answer:
The salt is Zn(NO3)2
When the residue is allowed to cool, its colour changes from yellow to white
The equation of the reaction is; 2Zn(NO3)2(s) --->2ZnO(s) + 4NO2(g) + O2(g)
Explanation:
Decomposition of Zn(NO3)2 is one of the routes by which ZnO is obtained. ZnO is a white insoluble powder which has a yellow colour when hot and a white colour when cold. It is an amphoteric substance used as a white pigment in paints and as a filler for rubber.
In a very pure form, it is used in cosmetic powders and creams as well as in medicinal ointments and lotions.
Also recall that NO2 is a brown gas and oxygen gas rekindles a glowing splint.
From the given choices, aluminum oxide is the only ionic
compound there. The ions present are Al3+ and O2-. Aluminum is a
chemical compound of aluminum and oxygen with the chemical formula Al2O3. It is
the most frequently happening of numerous aluminum oxides, and precisely recognized
as aluminum (III) oxide.
Answer:
c. Hfus is always negative.
Explanation:
Because energy is released when fusing solids
