4. Barry Um has a sample of a compound which weighs 200 grams and contains
only carbon, hydrogen, oxygen and nitrogen. By analysis, he finds that it
contains 97.56 grams of carbon, 4.878 g of hydrogen, 52.03 g of oxygen and
45.53 g of nitrogen. Find its empirical formula.

Explanation:

1. Build a table with the analysis and the atomic masses

Element      Massgrams    Atomic mass

                        (g)                    g/mol

   C               97.56                 12.011

   H                 4.878                 1.008    

   O                52.03               15.999

   N                45.53               14.007

2. Divide the mass of each element by its atomic mass to obtain the amount of each element in moles

Element      Massgrams    Atomic mass     moles

                        (g)                    g/mol

   C               97.56                 12.011             8.1226

   H                 4.878                 1.008           4.8393

   O                52.03               15.999           3.2521

   N                45.53               14.007           3.2505

3. Divide each amount in moles by the least number of moles: 3.2505

Element       moles          ratio

   C              8.1226         2.5

   H              4.8393         1.5

   O              3.2521          1.0

   N              3.2505         6.0

4. Mutiply each ratio by 2 to obtain whole numbers

Element      ratio    ratio

   C              2.5        5

   H              1.5         3

   O              1.0         2

   N              1.0         2

5. Write the empirical formula

The mole ratios are represented with suberscripts in the chemical formula:

.

they all get energy from eating other animals, dead animals to be more precise.

hienas tends to steal pray from other animals. crows and vultures tend to eat dead animals and leftovers.

hope it ,

bioteacher101