Question

In victor Mayer’s method 0.2 g of a volatile compound on volatilisations gave 56ml of vapour at STP. Its molecular weight is

Answer 1

Answer:

80

Explanation:

56ml volume of air is displaced by 0.2 gm organic compound

22400ml volume of air displaced by 0.2gm organic compiund

= 22400 x 0.2 / 56 = 80

Victor Meyer Method is used for volatile organic compounds. A known mass of the compound is vaporised in an instrument called Victor Meyer tube. The vapours obtained, displace an equal volume of air into a graduated tube. The volume of vapours is measured and reduced to STP.

1. Let the volume of vapours at STP be V mL
2. 22400 mL of vapours are obtained from 1 mole of the compound.
3. V mL of vapours are obtained from (V/ 22400) mL of the compound
4. Mole= W/Mw

Therefore,

W/Mw = V/22400

From this, the molecular weight of the compound can be determined.

Answer 2

Answer:

80

Explanation:

56 mL of the vapour of O.C (displaced 56 mL air) weigh=0.2 g

22400 mL vapour of O.C (displaced 56 mL air) weigh =0.256×22400

                                                                                          =80g

hope this help you  :)