In this experiment we will be mixing two ionic compounds: potassium chromate and lead nitrate; both are soluble in water. This will be demonstrating a double-replacement reaction/reactions between cations and anions. If a reaction does occur it will form a precipitate due to one of the newly formed compounds not being soluble in water.
Once the experiment was completed there was what appears to be a “solid” substance remaining in the test tube. This shows that a reaction occurred.
1. Once in the ChemLab-Cations and anion reactions. You will need to obtain a 100mL beaker and 50mL of potassium chromate. This will be done by clicking on the Chemicals section of the toolbar, then selecting 1M Potassium Chromate, change the volume to 50mL, then select to add the Potassium Chromate to a new 100mL beaker.
2. Next, you will need to left click on the beaker, then select Chemicals from the toolbar, select 1M Lead Nitrate, change the volume to 50mL (ensure that the window indicated that it will be placed in the existing beaker.
3. Now you will need to filter the precipitate. Obtain an Erlenmeyer flask and a Buchner funnel. This will be done by selecting from the Equipment section on the toolbar and selecting Erlenmeyer Flask-250mL. Next, right click on the flask and select Buchner Funnel. Right click on the beaker and select Pour/Decant. Move the beaker above the funnel and you will see a white area at the bottom of the flask.
4. Lastly, you will need to record the weight of the precipitate. Right click on the flask and select Buchner Funnel. A message will appear asking if “An amount of solid was found present in the filter, what action would you like to take?”, select place solid into 50mL Test Tube. You will now see the Test Tube with the precipitate in the bottom, right click on the Test Tube and click on show weight, the weight of the precipitate will appear, record the weight.
Observations and Results
There is a small amount of precipitate in the bottom of the test tube that appears yellow in color with some dots in the solution.
Weight of filtered precipitate: 16.160g
Due to a reaction occurring between the cations and the anions this has caused a reaction, therefore creating a “solid” that is not water soluble.
When mixing the two ionic compounds: potassium chromate and lead nitrate and then filtering the solution this revealed a “solid” substance that remained. This substance is not soluble in water hence it was left behind after filtering. This shows that a reaction occurred between the cations and anions.
This lab represented a double-replacement reaction of the ionic compounds: potassium chromate and lead nitrate. Once these compounds were mixed and then filtered it revealed a “solid” substance that remained. This confirms that a reaction occurred between the cations and anions, and ultimately formed a new substance.