Write the balanced chemical equation, including the physical states, for the reaction that occurs when the test solution reacts

with excess sodium sulfide, $N{a}_{2}S.$

balanced equation:Procedures

Experiment: Determine Limiting and Excess Reactants

Part $1$: Prepare the Test Solution and Test Standards

Record all observations for this part in Table $13\mathrm{.}1.$

Take one $50mL$ beaker and one $50mL$ graduated cylinder from the Containers shelf. Measure $20\mathrm{.}0mL6M$ ammonia

in the graduated cylinder, recording the exact volume at the meniscus, then transfer to the beaker. Put the used

graduated cylinder in the sink.

Take a new $50mL$ graduated cylinder from the Containers shelf. Take $0\mathrm{.}4M$ zinc sulfate from the Materials shelf. Use

the graduated cylinder to measure $20\mathrm{.}0mL,$ record the amount, then transfer to the beaker that contains the ammonia

solution. Put the used graduated cylinder in the sink. You have now prepared the test solution.

Take two test tubes and one $10mL$ graduated cylinder from the Containers shelf and place them on the workbench.

Double$-$click on the test tubes and label them "test tube standard $1"$ and "test tube standard $2".$

Take $0\mathrm{.}1$ M copper$($II$)$ sulfate from the Materials shelf and measure $6\mathrm{.}0mL$ into the graduated cylinder. Double$-$click on

the graduated cylinder and record the exact volume at the meniscus. Transfer the liquid to the test tube $1$ and record the

color of the solution to reference later. Put the graduated cylinder in the sink.

Take a new $10mL$ graduated cylinder from the Containers shelf. Take $0\mathrm{.}1M$ sodium sulfide from the Materials shelf

and measure $6\mathrm{.}0mL$ into the graduated cylinder. Double$-$click on the graduated cylinder and record the exact volume at

the meniscus. Transfer the liquid to test tube $2$ and record the color of the solution to reference later. Put the used

graduated cylinder in the sink.

Take a new $10mL$ graduated cylinder from the Containers shelf. Using the $10mL$ graduated cylinder, measure $2mL$ of

the test solution and pour $2mL$ into each of the two test tubes. Record any color changes and whether a precipitate

forms. The reaction should happen fairly quickly.

The first test tube shows what an excess of copper$($II$)$ sulfate looks like, and the second test tube shows what an excess

of sodium sulfide looks like. These are the standards against which to compare other samples. Double$-$click on each test

tube and label the tube for reference.Write the balanced chemical equation, including the physical states, for the reaction that occurs when the test solution reacts

with excess sodium sulfide, $N{a}_{2}S.$

balanced equation: