\begin{tabular}{|l|l|l|l|}
\hline \multicolumn{1}{|c|}{Chemical Name} & \multicolumn{1}{|c|}{Chemical Formula} & \multicolumn{1}{c|}{Chemical Name} & \multicolumn{1}{c|}{Chemical Formula} \\
\hline acetate & [tex]$C_2H_3O_2^{-}$[/tex] & nitrite & [tex]$NO_2^{-}$[/tex] \\
\hline carbonate & [tex]$CO_3^{2-}$[/tex] & ammonium & [tex]$NH_4^{+}$[/tex] \\
\hline hypocarbonite & [tex]$CO^{2-}$[/tex] & cyanide & [tex]$CN^{-}$[/tex] \\
\hline \begin{tabular}{l}
hydrogen carbonate \\
(bicarbonate)
\end{tabular} & [tex]$HCO_3^{-}$[/tex] & hydroxide & [tex]$OH^{-}$[/tex] \\
\hline chlorite & [tex]$ClO_2^{-}$[/tex] & peroxide & [tex]$O_2^{2-}$[/tex] \\
\hline hypochlorite & [tex]$ClO^{-}$[/tex] & phosphate & [tex]$PO_4^{3-}$[/tex] \\
\hline & & & \\
\hline
\end{tabular}

Select the correct answer.

What is the chemical name of the compound [tex]$Na_2CO_3$[/tex]? Use the list of polyatomic ions and the periodic table to help you answer.

A. sodium carbon oxide
B. sodium carbonate
C. sodium(ii) carbonate
D. sodium oxalate



Answer :

To solve the problem of identifying the correct chemical name for [tex]\(Na_2CO_3\)[/tex], we need to break down the components of the chemical formula and use the provided list of polyatomic ions.

### Step-by-Step Solution:

1. Identify [tex]\(Na_2\)[/tex]:
- [tex]\(Na\)[/tex] stands for sodium. There are two [tex]\(Na\)[/tex] atoms in the formula.

2. Identify [tex]\(CO_3\)[/tex]:
- [tex]\(CO_3\)[/tex] is listed in the table with a charge of [tex]\(2-\)[/tex]. This polyatomic ion is called carbonate.

3. Determine the Name of the Compound:
- Combine the names of the elements and polyatomic ion:
- The sodium ([tex]\(Na\)[/tex]) does not change its name.
- The polyatomic ion [tex]\(CO_3^{2-}\)[/tex] is called carbonate.
- Therefore, the chemical name for [tex]\(Na_2CO_3\)[/tex] is sodium carbonate.

4. Choosing the Correct Answer from the Options Provided:
- A. sodium carbon oxide (Incorrect, because there's no such naming convention in this context).
- B. sodium carbonate (Correct, because this matches our identification and naming).
- C. sodium(ii) cartonate (Incorrect, as this is a malformed name with no standard naming convention 'cartonate').
- D. sodium cxalate (Incorrect, as oxalate has the formula [tex]\(C_2O_4^{2-}\)[/tex], not [tex]\(CO_3^{2-}\)[/tex]).

Thus, the correct answer is:

B. sodium carbonate