If you find the mass of a sample to be 42.1 g and the actual mass is 42.0 g. your percent error would be what?

0.24%

Explanation:

To find the percent error, first subtract the actual value by the expected value.  You can ignore the sign of the difference.

42.0 - 42.1 = -0.1 = 0.1

Divide the difference by the expected value and multiply by 100%.

0.1/42.1 = 0.0024 × 100% = 0.24%

The percent error is 0.24%.

3

explanation:

the ratio of the conjugate base to the acid required to attain the desired ph.