Pipets Weights of water using: Plastic 1 mL pipet Automatic Pipet o00 uL Automat
ID: 3283501 • Letter: P
Question
Pipets Weights of water using: Plastic 1 mL pipet Automatic Pipet o00 uL Automatic Pipet 1000 uL 2 1,116 3. 7.041 4. 1 042 s. 1,04 Means: Fur 1000 nl:????marg. ; for U kl:i.aome a 1. 0.185 1. 0123 2. 0,9829 3. 0.987 4 4· 1.0287 2 1. .0160 2. D-0192 3. 0.D 200 4. O.0?? .02o 5. True (expected) weight of 1.00 mL(1000??) ofwater? _1.00 True (expected) weight of 20 ??of water? Compare your measurements of 1 mL of water using the automatic pipet to your measurements using a plastic 1 mL pipet: In your hands, which pipet is more accurate? Which is more precise? How did your measurements of 20 HL of water compare to the the expected value? How accurate were your measurements? How precise? Of the three pipets you used, which would you choose to transfer 50 ?L of wat from one container to another? Explain your choice. erExplanation / Answer
1. Mean (1000 uL pipet)= sum of all observations (of 1000 uL pipet) / no. of observtaions =1.02177 g
Mean (20 uL pipet)= sum of all observations (of 20 uL pipet) / no. of observtaions= 0.01908 g
Standard deviation (1000 uL pipet) = 0.041768
Standard deviation (20 uL pipet) = 0.01813
2. True value1= 1000 uL
True value2= 20 uL
3. Manual pipetts are more subect to human error.Automatic pipetts themselves regulate the rate of aspiration and dispensing so less cahnces for air to get into the column. Therefore autmatic ones are more precise and accurate both.