Home
Class 11
CHEMISTRY
Boron forms a variety of unusual compoun...

Boron forms a variety of unusual compounds with hydrogen. Achemist isolated `6.3 mg` of one of the boron hybrides in a glass bulb with a volume of `385 mL" at "25^(@)C` and a bulb pressure of 11 torr. the molecular mass of the boron hybride in g `mol^(-1)` is

A

`3.68`

B

`27.6`

C

`36.35`

D

`56.52`

Text Solution

Verified by Experts

The correct Answer is:
B
Assuming ideal gas law: `pV= nRT= (w)/(M)RT implies M= (wRT)/(pV)`. Substituting values, we get
`M= (6.3 xx 10^(-3)g xx 0.082L atm mol^(-1) K^(-1)xx 298K)/(11"/"760 atm xx 385 xx 10^(-3)L)= 27.6g mol^(-1)`.
Promotional Banner

Similar Questions

Explore conceptually related problems

One gram of an alloy of Al and Mg when treated with excess of dilute HCI forms MgCI_2, AICI_3 and hydrogen. The evolved hydrogen collected over Hg at 0°C has a volume of 1.20 litres at 0.92 atm pressure. Calculate the composition of the alloy. ("AI" = 27, "Mg" = 24)

Two elements 'A' and 'B' form compounds having formula 'AB2' and 'AB_4' .When dissolved in '20 g' of benzene '(C_6 H_6), 1 g' of 'AB_2' lowers the freezing point by '2.3 K' whereas '1.0 g' of 'AB_4' lowers it by 1.3. K: The molar depression constant for benzene is 5.1 K kg mol −1. Calculate atomic masses of A and B.