An element X has a valency of H. Write its formula for carbonate?

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.

An Intiative by Sri Chaitanya

answer is C.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Concept- Valency is the number of electrons an atom required to achieve a stable octet configuration. If the last shell contains more than 4 electrons, it accepts electrons otherwise it loses electrons for stability.
Now, Element X has the same valency as that of H. The valency of H is 1. So, the valency of element X is also 1.
The formula of the carbonate ion is

C O_{3}^{2 -}

and thus the charge on the carbonate ion is -2.
The crisscross method is used to write the formula of an ionic compound. As per the crisscross method, the numerical value of each of the ionic charges crosses over to become the subscript of the other ion.
Therefore, the carbonate formed with element X is

.
Hence, the correct answer is 3.

Watch 3-min video & get full concept clarity

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE