Question

Find the empirical formula of the compound ribose, a simple sugar often used as a nutritional supplement. A 14.229 g sample of ribose was found to contain 5.692 g carbon, 0.955 g hydrogen, and 7.582 g oxygen. Show your work.

Answer 1

Answer:

CH2O

Explanation:

Firstly, we need to convert the masses of the elements to percentage compositions. This can be done by placing the mass of each element over the total mass multiplied by 100% . We can start with carbon.

C = 5.692/14.229 * 100 = 40%

O = 7.582/14.229 * 100 = 53.29%

H = 0.955/14.229 * 100 = 6.71%

We then proceed to divide each percentage composition by their atomic mass of 12, 16 and 1 respectively.

C = 40/12 = 3.333

O = 53.29/16 = 3.33

H = 6.71/2 = 6.71

Dividing by the smaller value which is 3.33

C = 3.33/3.33 = 1

O = 3.33/3.33= 1

H = 6.71/3.33 = 2

The empirical formula of the compound ribose is CH2O

Answer 2

Answer:

CH2O

Explanation:

First divide the given mass of each element by its relative atomic mass.

For carbon 5.692/12 = 0.47

For hydrogen 0.955/1 = 0.955

For oxygen 7.582/16= 0.47

Then we divide each by the lowest ratio

For carbon- 0.47/0.47 =1

For hydrogen- 0.955/0.47= 2

For oxygen- 0.47/0.47 = 1

Hence the empirical formula is CH2O