Question

Express your answer to three significant figures.
This balanced equation shows the reaction of sodium hydroxide and sulfuric acid:
2NaOH + H2SO4 - Na2SO4 + 2H20.
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
grams.

Answer 1

Answer: The theoretical mass of $Na_2SO_4$ is, 514 grams.

Explanation : Given,

Mass of $H_2SO_4$ = 355 g

Molar mass of $H_2SO_4$ = 98 g/mol

First we have to calculate the moles of $H_2SO_4$.

$\text{Moles of }H_2SO_4=\frac{\text{Given mass }H_2SO_4}{\text{Molar mass }H_2SO_4}$

$\text{Moles of }H_2SO_4=\frac{355g}{98g/mol}=3.62mol$

Now we have to calculate the moles of $Na_2SO_4$

The balanced chemical equation is:

$2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O$

From the reaction, we conclude that

As, 1 mole of $H_2SO_4$ react to give 1 mole of $Na_2SO_4$

So, 3.62 mole of $H_2SO_4$ react to give 3.62 mole of $Na_2SO_4$

Now we have to calculate the mass of $Na_2SO_4$

$\text{ Mass of }Na_2SO_4=\text{ Moles of }Na_2SO_4\times \text{ Molar mass of }Na_2SO_4$

Molar mass of $Na_2SO_4$ = 142 g/mole

$\text{ Mass of }Na_2SO_4=(3.62moles)\times (142g/mole)=514g$

Therefore, the theoretical mass of $Na_2SO_4$ is, 514 grams.