Answer:
Requirements for a correctly written chemical equation are reactants and products, their formula and valency
Explanation:
Formula of the given compound are -
1 - Potassium Hydroxide - 
2 - Calcium Nitrate - 
The requirements for a correctly written chemical equation are -
- Identifying reactants and products
- Formula of reactants and products
- Valency of elements
Example of word equation, formula equation, and chemical equation is as follows -
Aluminium + iron9(III)oxide ⇒ aluminium oxide + iron (word equation)
+
⇒
+
(formula equation)
+
⇒
+
(chemical equation)
Depression in freezing point (Δ

) =

×m×i,
where,

= cryoscopic constant =

,
m= molality of solution = 0.0085 m
i = van't Hoff factor = 2 (For

)
Thus, (Δ

) = 1.86 X 0.0085 X 2 =

Now, (Δ

) =

- T
Here, T = freezing point of solution

= freezing point of solvent =

Thus, T =

- (Δ

) = -
Explanation:
-plants that can absorb copper ions are grown on soil with low grade copper ores.
-the plants are burned and the copper compounds are within the Ash.
-copper ions can be leached from the Ash by adding sulphuric acid, this makes a solution of copper sulphate
-the displacement of scrap iron makes pure copper metals.
Actions form positive ions while anions forms negative