Formal Lab Report
TITLE: Toxicity Testing and Determining the LC50
INTRODUCTION: Our main objective for this experiment was to determine which three chemicals were going to be the most toxic to the brine shrimp by adding drops of vinegar, bleach and ammonia to the controlled water. We found that the vinegar was the most effective and the quickest. The ending results were very interesting when being compared to our hypothesis and we learned that some chemicals can react faster than others and each contains a different level of concentration.
HYPOTHESIS: For brine shrimp exposed to increasing concentrations of three chemicals, ammonia will have the highest LC-50 (toxicity), bleach will have the intermediate LC-50 (toxicity) and vinegar will have the lowest LC-50 (toxicity).
MATERIALS AND METHODS: For this experiment we use the following materials:
Petri dishes (4 per group)
Stop watch or clock
Safety goggles (1 for each person)
Brine shrimp
Brine solution (3.5% w/v NaCl and water) need 600 ml per class
Vinegar- need about 50 ml in small dropper bottle (1 per group)
Ammonia- need about 50 ml in small dropper bottle (1 per group)
Bleach- need about 50 ml in small dropper bottle (1 per group)
3 pipettes (1 ml) – each labeled for the respective contaminants
Pipette pumps
Grease pencils
Beakers (5 or 10 ml)
Graduated cylinders (25 ml)
Magnifiers or hand lens (minimum 2 per group)
Beakers (Extra large) for waste- one each labeled for Vinegar, Bleach and Ammonia
Beaker (Extra large) for tested Brine Shrimp
Our procedures consisted of eight steps.
Step 1- We all put on our safety goggles before gathering our materials.
Step 2- We gathered our 4 petri dishes and labeled them using a grease pencil. One petri dish labeled “C” for Control, “V” for Vinegar, “A” for Ammonia and “B” for Bleach.
Step 3- Once the petri dishes were labeled, we took a 25 ml cylinder and used a pipette to gather 12 brine shrimp to put inside of the cylinder. Using the measurement lines on the side of the cylinder,
INTRODUCTION: Our main objective for this experiment was to determine which three chemicals were going to be the most toxic to the brine shrimp by adding drops of vinegar, bleach and ammonia to the controlled water. We found that the vinegar was the most effective and the quickest. The ending results were very interesting when being compared to our hypothesis and we learned that some chemicals can react faster than others and each contains a different level of concentration.
HYPOTHESIS: For brine shrimp exposed to increasing concentrations of three chemicals, ammonia will have the highest LC-50 (toxicity), bleach will have the intermediate LC-50 (toxicity) and vinegar will have the lowest LC-50 (toxicity).
MATERIALS AND METHODS: For this experiment we use the following materials:
Petri dishes (4 per group)
Stop watch or clock
Safety goggles (1 for each person)
Brine shrimp
Brine solution (3.5% w/v NaCl and water) need 600 ml per class
Vinegar- need about 50 ml in small dropper bottle (1 per group)
Ammonia- need about 50 ml in small dropper bottle (1 per group)
Bleach- need about 50 ml in small dropper bottle (1 per group)
3 pipettes (1 ml) – each labeled for the respective contaminants
Pipette pumps
Grease pencils
Beakers (5 or 10 ml)
Graduated cylinders (25 ml)
Magnifiers or hand lens (minimum 2 per group)
Beakers (Extra large) for waste- one each labeled for Vinegar, Bleach and Ammonia
Beaker (Extra large) for tested Brine Shrimp
Our procedures consisted of eight steps.
Step 1- We all put on our safety goggles before gathering our materials.
Step 2- We gathered our 4 petri dishes and labeled them using a grease pencil. One petri dish labeled “C” for Control, “V” for Vinegar, “A” for Ammonia and “B” for Bleach.
Step 3- Once the petri dishes were labeled, we took a 25 ml cylinder and used a pipette to gather 12 brine shrimp to put inside of the cylinder. Using the measurement lines on the side of the cylinder,