Common Polyatomic Ions

\begin{tabular}{|c|c|c|c|}
\hline
Chemical Name & Chemical Formula & Chemical Name & 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
\end{tabular}

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Type the correct answer in the box. Express your answer to three significant figures.

This balanced equation shows the reaction of sodium hydroxide and sulfuric acid:

[tex]\[2 NaOH + H_2SO_4 \rightarrow Na_2SO_4 + 2 H_2O\][/tex]

In a laboratory experiment, a student mixes 355 grams of sulfuric acid with an excess of sodium hydroxide. What is the theoretical mass of sodium sulfate produced? Refer to the periodic table and the polyatomic ion resource.

The theoretical mass of sodium sulfate is [tex]$\square$[/tex] grams.



Answer :

To determine the theoretical mass of sodium sulfate produced when 355 grams of sulfuric acid reacts with an excess of sodium hydroxide, we need to follow a series of steps involving stoichiometry and conversions between mass and moles.

### Step-by-Step Solution:

1. Determine the molar mass of H₂SO₄ (Sulfuric Acid):
- The molar masses of the elements are:
- H (Hydrogen) = 1.008 g/mol
- S (Sulfur) = 32.06 g/mol
- O (Oxygen) = 16.00 g/mol
- The molar mass of H₂SO₄ is calculated as follows:
[tex]\[ \text{Molar mass of H₂SO₄} = (2 \times 1.008) + 32.06 + (4 \times 16.00) = 98.076 \text{ g/mol} \][/tex]

2. Calculate the number of moles of H₂SO₄:
- Given mass of H₂SO₄ is 355 grams.
- Number of moles of H₂SO₄ ([tex]\(n\)[/tex]) is calculated as:
[tex]\[ n = \frac{\text{mass}}{\text{molar mass}} = \frac{355 \text{ g}}{98.076 \text{ g/mol}} = 3.619641910355235 \text{ moles} \][/tex]

3. Determine the molar mass of Na₂SO₄ (Sodium Sulfate):
- The molar masses of the elements are:
- Na (Sodium) = 22.99 g/mol
- S (Sulfur) = 32.06 g/mol
- O (Oxygen) = 16.00 g/mol
- The molar mass of Na₂SO₄ is calculated as follows:
[tex]\[ \text{Molar mass of Na₂SO₄} = (2 \times 22.99) + 32.06 + (4 \times 16.00) = 142.04 \text{ g/mol} \][/tex]

4. Use the stoichiometric ratio from the balanced equation to find the moles of Na₂SO₄ produced:
- The balanced equation is:
[tex]\[ 2 \text{ NaOH} + \text{H₂SO₄} \rightarrow \text{Na₂SO₄} + 2 \text{H₂O} \][/tex]
- According to the balanced equation, 1 mole of H₂SO₄ produces 1 mole of Na₂SO₄.
- Therefore, the number of moles of Na₂SO₄ produced is equal to the number of moles of H₂SO₄ reacted:
[tex]\[ 3.619641910355235 \text{ moles of Na₂SO₄} \][/tex]

5. Calculate the mass of Na₂SO₄ produced:
- Mass of Na₂SO₄ is calculated as:
[tex]\[ \text{Mass} = \text{number of moles} \times \text{molar mass} = 3.619641910355235 \text{ moles} \times 142.04 \text{ g/mol} = 514.1339369468575 \text{ g} \][/tex]

### Final Answer:
The theoretical mass of sodium sulfate produced is approximately [tex]\(\boxed{514 \text{ grams}}\)[/tex].