Question & Answer: The molecular formula mass of this compound is 150 amu. What are the subscripts in the…..

Atomic weight of Hydrogen =1.0079

Atomic weight of Carbon= 12.0107

Atomic weight of Oxygen = 15.99

Here we can take 100gm of sample. For this ‘C’ contains 40.0gms(At. No.=6), 6.70gms of ‘H'(At. No.=1), 53.3gms of ‘O'(At. No.=8)

First we can calculate No. of moles

No. of moles of Hydrogen = Weigt / Atomic weight = 6.70 /1.01 =6.63 moles

No. of moles of Carbon = Weigt / Atomic weight = 40.0 /12 =3.33 moles

No. of moles of Nitrogen = Weigt / Atomic weight = 53.3/16 =3.33 moles

We can devide these values with smallest values.

‘H’ = 6.63/ 3.33 2

C = 3.33 /3.33 =1

O =3.33 /3.33 =1

CH₂O is the emperical formula. Actuval mass of sustance =150amu

The molecular weight of emperical formula is 30

 150/30=5

 5 * CH₂O=150

C₅H₁₀O₅ is molecular formula

Ans: 5, 10, 5