Question

An element ‘Z’ is trivalent. Write the balanced chemical equation for the reaction of the element ‘Z’ with oxygen to form its oxide.

Answer 1

Explanation:

Element is X. It is trivalent so it can form X

+3

a) X

2

O

3

b) XCl

3

Answer 2

Answer:

The balanced chemical equation will be:
4Z³⁺   +   3O₂   →   2Z₂O₃  

Explanation:

Valency of an element is the combining capacity of an element that corresponds to the number of hydrogen atoms can combine with that element.

We have given that the element Z is trivalent. So we can write it as Z³⁺. The valency of Z is 3. We know that the valency of oxygen is 2.

From the criss cross method when element Z and O will form the oxide of Z, their valency become the subscript of other element. Therefore the compound formed will be Z₂O₃.

Z³⁺   +   O₂   →   Z₂O₃  

The balanced chemical equation will be:

$4Z^{3+} \;\; + \; \; 3O_{2}\; \; \longrightarrow \; \; 2Z_{2}O_{3}$

For example, the oxide of aluminum (alumina) will be formed as:

$4Al^{3+} \;\; +\;\; 3 O_{2}\; \longrightarrow \; \; 2Al_{2}O_{3}$