Percent Error Formula: Find the % Error in Lab w/ 10 mL Water

AI Thread Summary
To calculate the percent error in the lab, the theoretical weight of water for 10 mL is 10 grams, while the experimental weight is derived from the meniscus reading of 8.9 mL, which corresponds to 7.57 grams. The percent error formula is (theoretical - experimental) / theoretical x 100. The confusion arises from the discrepancy between the expected volume of 10 mL and the measured volume of 8.9 mL. Clarifying the experimental procedure and understanding the meniscus reading is crucial for accurate calculations.
lindseyam
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Homework Statement


I need to find the percent error from a lab I did in class. i have all the data but I don't know what would be used for the theoretical weight and experimental weight in the percent error formula. I used 10 mL, 25 mL, and 50 mL of water in a graduated cylinder. I'll just used the 10 mL information. I got 8.9 mL for the meniscus. The weight of the cylinder was 75.35 grams and with the water, 82.92 grams which makes the weight of the water 7.57 grams. So the problem once again is what I would use for the theoretical weight and experimental weight in the percent area formula. I would ask my teacher but he's not that friendly and makes me feel like an idiot.


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Please describe the experimental procedure, experiment is unclear to me - I can't see a connection between 10 mL, 8.9mL and 7.57g.
 
Borek said:
Please describe the experimental procedure, experiment is unclear to me - I can't see a connection between 10 mL, 8.9mL and 7.57g.

I had 10 mL of water in the graduated cylinder and got a meniscus of 8.9 and the water weighs 7.57 grams. and the percent error formula is (theoretical - experimental) divided by theoretical X 100. Would theoretical and experimental be?
 
It still doesn't make sense.

lindseyam said:
I had 10 mL of water in the graduated cylinder and got a meniscus of 8.9

I don't get it. If the meniscus was at 8.9, you had 8.9 mL of water in cylinder, not 10 mL.

Would theoretical and experimental be?

:confused:
 
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