Question

X is an ionic compound containing
only magnesium, aluminium and
oxygen. Which of the following can be
the formula of X?
a. Mg2Alo4
b. MgAl204
C. MgAlO4
d. Mg4Alo2​

Answer 1

Answer:-

The formula of 'X' is MgAl₂O₄ [Option.b]

Explanation:-

→ Charge of Magnesium ion = +2

→ Charge of Aluminium ion = +3

→ Charge of Oxide ion = -2

Now, we know that net charge of an ionic compound is always zero. So among the given options, the compound having net charge zero will be the answer.

For Option (a):-

Net charge :-

= 2(+2) + 1(+3) + 4(-2)

= 4 + 3 - 8

= -1

For option (b):-

Net charge :-

= 1(+2) + 2(+3) + 4(-2)

= 2 + 6 - 8

= 0

For option (c):-

Net charge :-

= 1(+2) + 1(+3) + 4(-2)

= 2 + 3 - 8

= -3

For option (d):-

Net charge :-

= 4(+2) + 1(+3) + 4(-2)

= 8 + 3 - 8

= +3

________________________________

The net charge in MgAl₂O₄ is zero, so it is the required answer!

Answer 2

Answer:

X is an ionic compound containing

only magnesium, aluminium and

oxygen. Which of the following can be

the formula of X?

a. Mg2Alo4

b. MgAl204

C. MgAlO4

d. Mg4Alo2

Answer:

b) MgAl2O4