Questions: A similar sort of experiment could be carried out using quite a few other combinations of chemicals. An example is the combination of Na2SO4 and Ba(NO3)2 to form BaSO4. Suppose in conducting the experiment with those substances it was found that the addition of Na2SO4 to the supernatant produced a precipitate. Which of the two species is the limiting reactant in that case? Explain your reasoning.

A similar sort of experiment could be carried out using quite a few other combinations of chemicals. An example is the combination of Na2SO4 and Ba(NO3)2 to form BaSO4. Suppose in conducting the experiment with those substances it was found that the addition of Na2SO4 to the supernatant produced a precipitate. Which of the two species is the limiting reactant in that case? Explain your reasoning.

Transcript text: 3. A similar sort of experiment could be carried out using quite a few other combinations of chemicals. An example is the combination of $\mathrm{Na}_{2} \mathrm{SO}_{4}$ and $\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}$ to form $\mathrm{BaSO}_{4}$. Suppose in conducting the experiment with those substances it was found that the addition of $\mathrm{Na}_{2} \mathrm{SO}_{4}$ to the supernatant produced a precipitate. Which of the two species is the limiting reactant in that case? Explain your reasoning.

Solution

Solution Steps

Step 1: Identify the Reaction

The chemical reaction between sodium sulfate ($\mathrm{Na}_{2} \mathrm{SO}_{4}$) and barium nitrate ($\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2}$) can be written as: \[ \mathrm{Na}_{2} \mathrm{SO}_{4} + \mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2} \rightarrow 2 \mathrm{NaNO}_{3} + \mathrm{BaSO}_{4} \] In this reaction, barium sulfate ($\mathrm{BaSO}_{4}$) is the precipitate.

Step 2: Understand the Experiment

The problem states that the addition of $\mathrm{Na}_{2} \mathrm{SO}_{4}$ to the supernatant (the liquid remaining after the precipitate has been removed) produces a precipitate. This indicates that there is still some $\mathrm{Ba}^{2+}$ ions left in the solution.

Step 3: Determine the Limiting Reactant

Since adding more $\mathrm{Na}_{2} \mathrm{SO}_{4}$ results in the formation of more $\mathrm{BaSO}_{4}$ precipitate, it means that there is an excess of $\mathrm{Ba}^{2+}$ ions in the solution. Therefore, the $\mathrm{Na}_{2} \mathrm{SO}_{4}$ must have been completely consumed in the initial reaction, making it the limiting reactant.