A student calculated the percent by mass of water in a hydrate as 14.2%. A hydrate is a compound that contains water as part of its crystal structure. If the accepted value is 14.7% the students percent error was
Answers
=5*142*10/147
=710*10/147
=4.82*20
=48.2% is the percentage error
Percentage error
Percentage error formula is used to determine the degree of the precision of your calculations to the accepted (or theoretical) values.
The percentage error is calculated by subtracting the accepted value from an experimental value. The next step is to divide this difference by the accepted value and multiply the dividend by 100.
Percentage error formula
( Experimental value - accepted value ) ÷ Theoretical value × 100%
⇒ In this question the accepted value ( theoretical value) is 14.7% and the experimental value is 14.2%
Therefore the percentage error = (14.2 - 14.7) ÷ 14.7 × 100%
= -0.5 ÷ 14.7 × 100%
= -3.401360544%
The students % error therefore was -3.401360544