# Chemistry

posted by .

I have to find the percentage of error. The accepted value is 11.35, while the value I got is 2.564. I got 2.564-11.35/11.35, and got a negative answer. Can percentages of error be negative? Thanks-Coralie.

• Chemistry -

The reason that your value is negative is that, it depends on which number you put first, when subtracting the accepted value from the experimental actual value, you have to put a | | (absolute sign) around the subtracted values. (that means that the value is accepted as being possitive,even if the value comes out negative because the actual experimental value was smaller than the accepted value.

so it comes out as..
| 2.564- 11.35|/11.35 x 100 = 77.41% error

It can't be negative.

• Chemistry -

Some profs like to use the absolute value so they always subtract the larger number minus the smaller number (so as to get a positive value) and divide by the accepted value and that times 100. The same rational applies to using the | | to obtain the absolute value as Christina has answered. But to answer your question, yes, there can be a negative value. And some profs like to use the negative value so they ALWAYS subtract it this way.
[(exp value - accepted value)/accepted value]*100 which ALWAYS gives a negative value if the experimental value is lower than the accepted value and ALWAYS gives a positive value if the experimental value is higher than the accepted value. The rationale of those profs is that the sign (negative or positive) tells them immediately if the result was too high or too low. I never worried about that piece of information because if it was in error more than about 0.2% to 0.4%, that was too much for me and I started over. I hope I didn't provide far more information than you wanted.

## Similar Questions

1. ### Chemistry (check)

12) Relative error is also called _______ I got accepted value decimal error?
2. ### Chemistry

How do you find Absolute error and how do you find relative error?
3. ### chemistry

Based on the experimental data, I was able to calculate the experimental pKa value which is 5.04 and the literature value of the pKa for KHP is 5.51. If I would be computing for the relative error between the two pKa's it would be …
4. ### Calculus

Estimate delta(x) using the Linear Approximation and use a calculator to compute both the error and the percentage error. f(x)=cosx a=(pi/4) delta(x)=.06 delta(x)= ______ i got this part and it's -.04242 The error in Linear Approximation …
5. ### Percent error?

What is the formula for percent-error? It's either: %error= (your value/accepted value)*100 or %error= (accepted value/your value)*100 I'm pretty sure it's the first one, but I also heard it can go either way. I tried both ways but
6. ### algebra

find the minimum value of f(x,y) equals x minus 4y for the feasible region. i did the promblem and got negative 10 but i did it again and got 0. my other two chooses can be either negative 2 or negative 4.if not any i need help. please …
7. ### Algebra

I distributed 3x^2+x-10=f(x) to find the zeroes. My book's answer was (3x-5)(x+2). When I distributed this to make sure I got the original function, I got 3x^2-x-10. Is this still an acceptable way to factor it even though the x is …
8. ### physics please

there are nearly (pi) x (10^7) seconds in one year. find the percentage error in this approximation, where percentage error is defined as abs value[ (assumed value - true value)/ true value] x 100% to find the true value I did: (365 …
9. ### Algebra 2

Absolute Value Equations Will someone please check to see if I am doing this correct?
10. ### chemistry

It is ok to have a negative percent error?

More Similar Questions