To calculate the theoretical yield of sodium sulfate (\( \text{Na}_2\text{SO}_4 \)) from the reaction between sulfuric acid (\( \text{H}_2\text{SO}_4 \)) and sodium hydroxide (\( \text{NaOH} \)), we can start with the balanced chemical equation for the reaction:
\[ \text{H}_2\text{SO}_4 (aq) + 2 \text{NaOH} (s) \rightarrow \text{Na}_2\text{SO}_4 (aq) + 2 \text{H}_2\text{O} (l) \]
Step 1: Calculate the moles of each reactant.
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Moles of sulfuric acid (\( \text{H}_2\text{SO}_4 \)):
The molar mass of \( \text{H}_2\text{SO}_4 \) is calculated as: \[ 2(1.01) + 32.07 + 4(16.00) = 98.09 , \text{g/mol} \]
Now, we find the moles of \( \text{H}_2\text{SO}_4 \): \[ \text{Moles of } \text{H}_2\text{SO}_4 = \frac{6.87 , \text{g}}{98.09 , \text{g/mol}} \approx 0.0700 , \text{mol} \]
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Moles of sodium hydroxide (\( \text{NaOH} \)):
The molar mass of \( \text{NaOH} \) is: \[ 22.99 + 1.01 + 16.00 = 40.00 , \text{g/mol} \]
Now, we find the moles of \( \text{NaOH} \): \[ \text{Moles of } \text{NaOH} = \frac{10.0 , \text{g}}{40.00 , \text{g/mol}} = 0.250 , \text{mol} \]
Step 2: Determine the limiting reactant.
According to the balanced equation, 1 mole of \( \text{H}_2\text{SO}_4 \) reacts with 2 moles of \( \text{NaOH} \).
From the moles calculated:
- Moles of \( \text{H}_2\text{SO}_4 \) = 0.0700 mol
- To react completely with 0.0700 mol of \( \text{H}_2\text{SO}_4 \), we need: \[ 2 \times 0.0700 , \text{mol} = 0.140 , \text{mol of NaOH} \]
We have 0.250 mol of \( \text{NaOH} \), which is more than enough. Therefore, \( \text{H}_2\text{SO}_4 \) is the limiting reactant.
Step 3: Calculate the theoretical yield of sodium sulfate.
From the balanced equation, 1 mole of \( \text{H}_2\text{SO}_4 \) produces 1 mole of \( \text{Na}_2\text{SO}_4 \).
Thus, the moles of \( \text{Na}_2\text{SO}_4 \) produced will be equal to the moles of the limiting reactant \( \text{H}_2\text{SO}_4 \): \[ \text{Moles of } \text{Na}_2\text{SO}_4 = 0.0700 , \text{mol} \]
Now we calculate the mass of \( \text{Na}_2\text{SO}_4 \): The molar mass of \( \text{Na}_2\text{SO}_4 \) is: \[ 2(22.99) + 32.07 + 4(16.00) = 142.04 , \text{g/mol} \]
Now, we find the mass of \( \text{Na}_2\text{SO}_4 \): \[ \text{Mass of } \text{Na}_2\text{SO}_4 = 0.0700 , \text{mol} \times 142.04 , \text{g/mol} \approx 9.94 , \text{g} \]
Final Result:
The theoretical yield of sodium sulfate, rounded to the correct number of significant digits (three significant figures), is: \[ \boxed{9.94 , \text{g}} \]