14.1: Determination of Kc Prep
- Page ID
- 10 Lab quests
- 10 Colorimeters
- 10 plastic cuvettes
- 50 10mL volumetric flasks
- 10 thermometer probes
- 4.0 L of 1.0M HNO3
- 2.0 L of 0.0020M Fe(NO3)3 made up in 1.0M HNO3
- 1.0 L of 0.0020M KSCN
- 750 mL of 0.200M Fe(NO3)3 in 1.0M HNO3
- 500 mL of 1.0 M HNO3
Instructions for making solutions:
1. Make the 1.0M HNO3 solution first. You can make this in the large carboy in the prep room. There may be enough already, or use what is there. Any dilution should be made with distilled water.
2. Prepare the KSCN solution next. This is made in distilled water. Make fresh. When cleaning up the lab, please dispose of any extra KSCN.
3. Prepare the 0.0020M Fe(NO3)3 solution. Use solid Fe(NO3)3·9H2O. You will need 1.62g of the solid to make the 2.0 L of solution. NOTE: Use the 1.0M HNO3 solution prepared above to dissolve and dilute the solid.
4. Prepare the 0.200M Fe(NO3)3 solution. Dissolve 60.58 g of the solid iron (III) nitrate nonahydrate (same solid as in step 3) in the 1.0M HNO3. Dilute to 750 ml. You may need to use two different volumetric flasks to do this (500mL and 250mL). Mix the two together before bottling.
5. Place 0.0020M Fe(NO3)3 and 0.0020M KSCN in dispenser bottles with repipetter in each hood. Use the 30 mL repipetter for Fe(NO3)3 and 5 mL repipetter for KSCN. Place a 50 mL beaker below repipetter to catch drips.
6. Make five bottles of 0.20M Fe(NO3)3 (Step 4) and label with a different color than the solution in made in step 3. Please also label this solution at STD.
7. Make five 100 mL bottles of HNO3.
Waste bottles are needed
- Nitric Acid – Flame over Circle – oxidizer; Corrosion – corrosive to metals; Corrosion – skin corrosion/burns; Corrosion – eye damage; Skull and crossbones – toxic if inhaled
- Iron III Nitrate – Corrosion – skin corrosion/burns; Corrosion – eye damage
- Potassium Thiocyanate – Exclamation point – skin irritant; Exclamation point – respiratory tract irritant, harmful if swallowed; Exclamation point – aquatic toxicity