Question

Acetic Acid contains carbon hydrogen and oxygen 4.24 gram of sample of Acetic Acid on complete complete combustion gave 6.21 gram of Co2 and 2.54 of H2O the molecular mass of Acetic acid is 60 find empirical formula of acetic acid and molecular formula of acetic acid ​

Answer 1

Answer:

We calculate the no of moles of CO2, H2O and Acetic Acid

6.21/44 = 0.14 moles

2.54/18 = 0.14 moles

4.24/60 = 0.07 moles

If we calculate the mole ratio (0.14/0.07) we see that one mole of acetic acid produces two moles of CO2 and two moles of water

We can write this in an Eq:

CxHyCOOH + 2O2 — 2CO2 + 2H20

Now using simple mathematics we can calculate both x and y

As both sides of the equation should have equal atoms of an element we see that for Carbon

x+1= 2

x= 2–1

x=1

And for Hydrogen

y+1= 4

y= 4–1

y= 3

Putting these values into the formula above we find the molecular formula for acetic acid that is CH3COOH.

For the empirical formula we can write the molecular formula in terms of the no of atoms of each element present and then reduce it to its simples form

i.e C2H4O2/2 which gives the Empirical formula as CH2O.