Question

Suppose you performed this experiment, and the percentage difference from the accepted value of the density of copper and your value was very large, let’s say 3000%. However, the standard deviation of your dataset was tiny; let’s say 0.01 g/cm. What conclusions can you draw about this discrepancy?

Answer 1

Answer:

The answer is 2%

Step-by-step explanation:

Steps to Calculate the Percent Error

Subtract the accepted value from the experimental value.

Take the absolute value of step 1

Divide that answer by the accepted value.

Multiply that answer by 100 and add the % symbol to express the answer as a percentage.

Now let’s try an example problem.

You are given a cube of pure copper. You measure the sides of the cube to find the volume and weigh it to find its mass. When you calculate the density using your measurements, you get 8.78 grams/cm3. Copper’s accepted density is 8.96 g/cm3. What is your percent error?

Solution:

experimental value = 8.78 g/cm3

accepted value = 8.96 g/cm3

Step 1: Subtract the accepted value from the experimental value.

8.78 g/cm3 – 8.96 g/cm3 = -0.18 g/cm3

Step 2: Take the absolute value of step 1

|-0.18 g/cm3| = 0.18 g/cm3

Step 3: Divide that answer by the accepted value.Percent Error Math 3

Step 4: Multiply that answer by 100 and add the % symbol to express the answer as a percentage.

0.02 x 100 = 2

2%

The percent error of your density calculation was 2%.