Question

Maleic acid is an organic compound composed of 41.39% , 3.47% , and the rest oxygen. If 0.378 mole of maleic acid has a mass of 43.8 g, what are the empirical and molecular fomulas of maleic acid?

Answer 1

Answer:

Empirical CHO

molecular C4H4O4

Explanation:

From the question, we know that it contains 41.39% C , 3.47% H and the rest oxygen. To get the % composition of the oxygen, we simply add the carbon and hydrogen together and subtract from 100%.

This means : O = 100 - 41.39 - 3.47 = 55.14%

Next is to divide the percentage compositions by their atomic masses.

C = 41.39/12 = 3.45

O = 55.14/16 = 3.45

H = 3.47/1 = 3.47

Now we divide by the smallest value which is 3.45. We can deduce that this will definitely give us an answer of 1 all through as the values are very similar.

Hence the empirical formula of Maleic acid is CHO

Now we go on to deduce the molecular formula.

To do this we need the molar mass. I.e the amount in grammes per one mole of the compound.

Now we can see that 0.378mole = 43.8g

Then 1 mole = xg

x = (43.8*1)/0.378 = 115.87 = apprx 116

[CHO]n = 116

(12 + 1 + 16]n = 116

29n = 116

n = 116/29 = 4

The molecular formula is thus C4H4O4