Question

The formula of Calcium Carbonate is :

• A. MgCO$_3$
• B. Na$_2$CO$_3$
• C. CuCO$_3$
• D. CaCO$_3$

Hint:

When writing chemical formulas for ionic compounds, always remember the charges of the individual ions (cations and anions) and combine them in a ratio that results in a net neutral charge for the compound.

Answer 1

The Correct Option is D

Step 1: Identify the ions involved in Calcium Carbonate.
Calcium is a Group 2 element and forms a cation with a +2 charge: Ca$^{2+}$.
Carbonate is a polyatomic anion with a -2 charge: CO$_3^{2-}$. Step 2: Determine the chemical formula by balancing charges.
To form a neutral compound, the total positive charge must balance the total negative charge.
Since calcium has a +2 charge (Ca$^{2+}$) and carbonate has a -2 charge (CO$_3^{2-}$), one Ca$^{2+}$ ion combines with one CO$_3^{2-}$ ion. The formula is therefore CaCO$_3$. Step 3: Evaluate the given options.
(1) MgCO$_3$: This is Magnesium Carbonate.
(2) Na$_2$CO$_3$: This is Sodium Carbonate.
(3) CuCO$_3$: This is Copper(II) Carbonate.
(4) CaCO$_3$: This is Calcium Carbonate. Step 4: Conclude the correct formula.
The correct formula for Calcium Carbonate is CaCO$_3$. $$(4) CaCO$_3$$$