Question

$A,B$ and $C$ are three elements forming a part of compound in oxidations states of +2, +5 and -2 respectively. What could be the compound?

• A. $A_2(BC{)}_2$
• B. $A_2(B{C}_4{)}_3$
• C. $A_3(B{C}_4{)}_2$
• D. $ABC$

Answer 1

Answer: (C)

$A_3(B{C}_4{)}_2$

The formula of a compound with elements A, B, C will be of the form Ax ByCz where x,y,z are the atomicities of individual atoms respectively.

The oxidation numbers of the elements A, B, C are +2, +5and -2 respectively.

A compound is always neutral, so the oxidation number of the compound is zero. Hence, the net oxidation number of the individual atoms is zero.

2x + 5y -2z= 0

Restricting it to conditions that maximum oxidation state could be +8 or -3, by Hit and Trial method, the possible solutions of (x,y,z) could be (1,2,6)

Both the sets are possible as the elements are unknown. Hence the compounds are A(BC3)2

Hence, the correct option is $C$