# Percent Error Formula

1. Sep 17, 2011

### lindseyam

1. The problem statement, all variables and given/known data
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.

2. Relevant equations

3. The attempt at a solution

2. Sep 17, 2011

### Staff: Mentor

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

3. Sep 17, 2011

### lindseyam

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?

4. Sep 17, 2011

### Staff: Mentor

It still doesn't make sense.

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