iLab, Week # 2
CATIONS AND ANION LAB
The purpose of this week’s lab is to learn to demonstrate a double-replacement reaction of ionic compounds. To accomplish this, two ionic compounds will be mixed together and the product will precipitate out of solution. In this procedure, the product must be precipitated out of the solution and then weighed.
For this lab, lead (II) nitrate (Pb(NO3)2) and potassium chromate (K2CrO4) will be reacted together to demonstrate double replacement reaction between 2 ionic compounds. This was shown when chromate replaced the nitrate and formed lead (II) chromate, and when the nitrate replaced the chromate and formed potassium nitrate, which is shown in the following equation:
Pb(NO3)2 + K2CrO4 PbCrO4 + 2KNO3
In this experiment, I found that when two ionic compounds that are soluble in water are combined together, specifically lead nitrate and potassium chromate, a double-replacement reaction occurs because precipitate formed.
Access the Model ChemLab software by clicking to the iLab Here link on the page. Follow the information to log into the lab. Once in, select Model ChemLab 2.4. After application loads, select the cations and anions lab out of the list provided for you in the box and then click OK.
To begin, use the Chemicals section of the toolbar. Select all chemicals from the dropdown menu. Select 1 M Potassium Chromate. Change the volume to 50mL. Make sure that the potassium chromate is added to a new 100 ml beaker. Click OK. A beaker should appear, and half of it will appear white; this is the 50mL of potassium chromate.
Left click on the beaker. A dotted line will appear. Under the chemicals section of the toolbar, select 1M of lead nitrate from the dropdown menu. Change the volume to 50mL. Make sure you have indicated that the lead nitrate is to be “placed in picked” 100 mL beaker. Click Ok. This should be added to the same...