Question

Which of these is the percent of error in evaluating the molecular mass of a compound if the experimental value was 105.2 amu and the known value was 107.5 amu? f 2.1% g 4.2% h 3.3% j 1.0%

Answer 1

• The percent error, % error, is 2.1% (option f)

Step-by-step explanation:

1) Data:

a) Experimental value, m₁ = 105.2 amu

b) Known value, m = 107.5 amu

b) % error = ?

2) Formulae:

a) absolute error = | experimental value - known value|

b) % error = [ absolute value / known value ] × 100

3) Solution:

a) absolute error = | m₁ - m | = | 105.2 amu - 107.5 amu | = 2.3 amu

b) % error = [ 2.3 amu / 107.5 amu ] × 100 = 2.1% ← answer