LD 50 Essay

Submitted By Tick-Jellison
Words: 557
Pages: 3

Semi Metals
Wendy Mora
Christopher Jellison
Alyssa Hernandez
Period 2

LD­50 Procedure
1. 0% Windex
2. 10% Windex
3. 1% Windex
4. 0.1% Windex
5. 0.01% Windex 2. Using the a graduated cylinder, measure out 25 mL of distilled water into the dish labeled
0%.

3. Place the lid of the 0% dish and set it aside. You will not be adding anything else to this water. 4. Obtain a portion of STOCK 12800 mg/kg Windex in the beaker that is provided. 5. PLace the dish labeled 10% in front of you. Using a pipette measure 2.5mL of stock
12800
mg/kg of windex and add to the 10% dish.
Make sure you do all this slow and carefully if you do not get it perfect you will need to start over! If you do not use all of the stock windex place it back in the stock beaker. 6. Next, add 25 mL of distilled water to the 10% dish. Make sure the pipette is clean and rinse it in the dish by sucking up water and squirting it carefully back into the dish.(repeat about 5 times)
Then, stir carefully and thoroughly but do not spill! 7. Transfer some of the substance from the 10% dish that was just made and add 25 mL to the 1% dish. Do this with caution! If needed restart. If you have leftover return it to the 10% dish using the pipette. 8. Place the lid the to the side of the 10% dish. Then place it to the 0% dish. 9. Using the graduated cylinder, measure out 25 mL of distilled water to the 1% dish. Then rinse and carefully squirt it back into the into the dish roughly five times, then stir with caution and dont spill.

10. Absorb some of the 1% solution you just made and carefully add 50 drops of it to the dish labeled 0.1%. Any unused 1% solution left from what you absorbed should be returned to the
1% dish. 11. Place the lid onto the 1% dish and put it aside with the other dishes, you are now done with this dish. 12. Add 25 mL of distilled water to the 0.1% dish. Make sure to…