Salts that are insoluble in water are made by precipitation.
● Lead(II) iodide, PbI2, is insoluble in water.
● All nitrates are soluble in water.
● All sodium salts are soluble in water.
You are provided with solid lead(II) nitrate, Pb(NO3)2, and solid sodium iodide, NaI.
Describe how you would make a pure sample of lead(II) iodide by precipitation.
Your answer should include:
● practical details
● a chemical equation for the precipitation reaction.
Dissolve some of the solid NaI in one beaker containing distilled water. Dissolve some of the solid Pb(NO3)2 in another beaker containing distilled water. Pour the contents of one beaker into the other beaker. Stir and allow to stand for a minute or two. Set up a filter apparatus. Pour the contents of the mixture. Wash the remaining precipitate from the beaker with distilled water, then wash the ppt in the filter paper with several portions of distilled water. Allow the contents of the filter paper to air dry. That will be solid PbI2.
Pb(NO3)2(aq) + 2NaI(aq) ==> PbI2(s) + 2NaNO3(aq)
Well, let me tell you, making a pure sample of lead(II) iodide is as simple as a juggling act! Here's how you can perform this chemical magic trick:
Practical Details:
1. Gather your equipment: You'll need solid lead(II) nitrate (Pb(NO3)2), solid sodium iodide (NaI), distilled water, beakers, a stirring rod, and a filtration device (such as a funnel and filter paper).
2. Safety first, my friend! Make sure you're wearing proper protective gear, like gloves and goggles. Safety's no laughing matter, you know!
3. Measure and pour a specific quantity of distilled water into a beaker. The amount will depend on the desired quantity of lead(II) iodide you want to make. Use your clever calculations to determine the appropriate amount.
4. Gradually add solid lead(II) nitrate (Pb(NO3)2) into the beaker with the distilled water. Stir the mixture gently to dissolve as much of the lead(II) nitrate as possible.
5. In a separate beaker, prepare a solution of solid sodium iodide (NaI) by dissolving it in distilled water. You can make a witty observation about the sodium iodide if you like, but just be careful not to lose your balance!
6. Pour the sodium iodide solution into the beaker containing the lead(II) nitrate solution. A sensational reaction will occur, my friend!
Chemical Equation:
The chemical equation for the precipitation reaction between lead(II) nitrate and sodium iodide can be represented as follows:
Pb(NO3)2 + 2NaI → PbI2 + 2NaNO3
Watch as lead(II) iodide, a beautiful yellow precipitate, forms in the beaker! But don't be overwhelmed by its radiance – you still have more tricks up your sleeve!
7. Allow the mixture to cool down, giving the lead(II) iodide plenty of time to settle at the bottom. Patience is key, my friend. Give the lead(II) iodide some room to show off its insoluble nature.
8. Once the lead(II) iodide has settled, you can use a filtration setup to separate it from the liquid solution. Use a filter paper and a funnel to collect the pure, solid lead(II) iodide. Don't forget to catch it with style!
9. Rinse the collected lead(II) iodide with some chilled distilled water to remove any impurities that might still be clinging to it. We want our lead(II) iodide to shine like a star!
10. Finally, transfer the lead(II) iodide onto a watch glass or a weighing boat, and let it dry completely. Soon, you'll have a pure sample of lead(II) iodide, ready to take center stage!
And there you have it, my friend, a pure sample of lead(II) iodide! Now, wasn't that a performance full of scientific laughter?
To make a pure sample of lead(II) iodide (PbI2) by precipitation, you would need solid lead(II) nitrate (Pb(NO3)2) and solid sodium iodide (NaI). Here's a step-by-step procedure:
1. Start by measuring equal amounts (usually around 1-2 grams) of solid lead(II) nitrate and solid sodium iodide. It's important to use equal amounts to ensure the stoichiometry of the reaction.
2. Dissolve each solid in separate beakers containing distilled water. This can be done by adding a small amount of water and stirring until the solids have completely dissolved.
3. Once both compounds are dissolved, slowly pour the sodium iodide solution into the beaker containing the lead nitrate solution. It's important to pour it slowly to ensure proper mixing.
4. As soon as the two solutions are mixed, a yellow precipitate of lead(II) iodide will form. This is because lead(II) iodide is insoluble in water.
5. Allow the mixture to sit undisturbed for some time, preferably a few minutes, to ensure complete precipitation of lead(II) iodide.
6. Once the precipitate has settled, carefully decant the liquid (supernatant) from the beaker without disturbing the solid.
7. Wash the precipitate by adding distilled water to the beaker and gently swirling to suspend the solid. Allow the solid to settle and decant the liquid again. Repeat this washing process 2-3 times to remove any impurities.
8. Once the washing is complete, collect the solid lead(II) iodide precipitate by carefully transferring it to a filter paper using a spatula or glass rod.
9. Allow the filter paper with the precipitate to air dry or use a gentle stream of air to expedite drying.
10. Once the lead(II) iodide is dry, carefully remove it from the filter paper and store it in a properly labeled, clean, and dry container.
The chemical equation for the precipitation reaction is:
Pb(NO3)2 (aq) + 2NaI (aq) → PbI2 (s) + 2NaNO3 (aq)
Note: It's important to handle all chemicals with caution and follow proper safety protocols, such as wearing gloves and goggles, while performing the experiment.
To make a pure sample of lead(II) iodide (PbI2) by precipitation, you will need solid lead(II) nitrate (Pb(NO3)2) and solid sodium iodide (NaI). Here are the steps to follow:
1. Start by weighing the desired amount of solid lead(II) nitrate (Pb(NO3)2) using an analytical balance. Take note of the mass for future calculations.
2. Dissolve the weighed lead(II) nitrate in a small volume of distilled water in a beaker or flask. Swirl or stir the mixture gently until the solid completely dissolves.
3. In a separate beaker or flask, weigh the required amount of solid sodium iodide (NaI) using an analytical balance. Again, record the mass of the sodium iodide for future calculations.
4. Once both the lead(II) nitrate and sodium iodide are properly weighed, pour the sodium iodide into the lead(II) nitrate solution. Stir the mixture gently to ensure thorough mixing.
5. As the two solutions combine, a precipitate of lead(II) iodide (PbI2) will form. The lead(II) iodide is insoluble in water and will appear as a yellow precipitate.
6. Allow the mixture to sit undisturbed for some time. This will allow the precipitate to settle at the bottom of the container.
7. Once the precipitate has settled, carefully decant the liquid (supernatant) from the container. Try to avoid disturbing the settled precipitate as you pour off the liquid.
8. Collect the remaining solid lead(II) iodide (PbI2) by carefully transferring it onto a filter paper using a spatula or a glass rod. The filter paper should be placed in a funnel supported over a flask to collect the filtrate.
9. Rinse the precipitate on the filter paper with a small amount of chilled distilled water to remove any traces of impurities. Allow the filtrate to drain into the flask.
10. Once the rinsing is complete, carefully transfer the filter paper with the lead(II) iodide onto a watch glass or a clean, dry surface. Allow the filter paper to air dry completely, leaving behind a pure sample of lead(II) iodide.
The chemical equation for the precipitation reaction can be represented as follows:
Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2NaNO3(aq)
This equation shows that when lead(II) nitrate (Pb(NO3)2) reacts with sodium iodide (NaI), lead(II) iodide (PbI2) precipitates out as a solid, while sodium nitrate (NaNO3) remains in the solution.