Presentation on theme: "Pat Benecewicz & Nathan Tompkins. * Compare concentrations of calcium from species to species. *Species: Cow Pig Deer * The two methods will be a whole."— Presentation transcript:
* Compare concentrations of calcium from species to species. *Species: Cow Pig Deer * The two methods will be a whole bone soaking and a ground-up bone soaking both in vinegar.
1.Soak the bones in boiling water to take the meat off just leaving the cartilage and bone. 2.Dry the bones overnight to remove any excess water off the bones. 3.Mass the femurs of each animal. 4.Put the femurs of each animal into a container and fill with vinegar to completely cover the bones. Let them soak for a week. 5.Take the tibias of each animal and cut a 1 inch section from each bone. 6.Crush the bone using a mortor and pestle and mass 5 grams of bone from the ground bones. 7.Put each 5g portion in a 150mL beaker and add 100mL of vinegar. Let them soak for a week. 8.Make a.01M solution of EDTA using 1.8600g of EDTA in 500mL of DI water. 9.Make a.1M solution of CaCO 3 using 1.000g of CaCO 3 in 2M HCl. Make an ammonia buffer with 6M NH 4 OH and adding 6M HCl until the pH is 10.00. 10.Standardize the EDTA solution with 3mL of the CaCO 3, 5mL of ammonia buffer, and 4 drops of calmagite indicator. Repeat two more times. 11.Remove the bones from the vinegar and allow the bones to dry. Record the volume of vinegar used for the whole bones. 12.Take 5mL of the vinegar solution, 5mL of ammonia buffer, and 4 drops of calmagite and titrate to the blue endpoint with the standardized EDTA. 13.Do this titration 3 times for each whole bone vinegar solution and 3 times for each ground up bone vinegar solution. 14.Calculate the concentration of calcium in each vinegar solution.
The purpose of this lab was to extract calcium from bones using vinegar (acetic acid). Acetic acid breaks apart CaCO 3 in the bones leaving the Ca 2+ ion floating in the vinegar and producing CO 2. This was observed when bubbles were forming around the bones when they were in the vinegar.
We formed a hypothesis that the hog would have the most calcium in it while the lamb would have the least amount of calcium in it. Our data proves otherwise. In both methods, the lamb had the highest percent of calcium. Grinding up the bones did not help extract more calcium than the whole bone soak.
A precipitate formed when we added the buffer to the vinegar. We found out that this white precipitate was Ca(OH) 2. Proving that we had our target ion in the vinegar solution. The precipitate disappeared once we reach the endpoint.