A gaseous mixture of three gases A, B and C has a pressure of 10 atm. The total number of moles of all the gases is 10. If the partial pressure of A and B are 3.0 and 1.0 atm respectively and if C has a mol/wt. of 2.0. what is the weight of C in g present in the mixture ?

Options

A. 8
B. 12
C. 3
D. 6

Answer

B

Explanation

`P = 10 atm, n_(A) + n_(B) + n_(C) = 10`
`p_(A) = 3.0 atm, p_(B) = 1.00 atm`
`p_(A) = underset(n_(A) + n_(B) + n_(C))overset(n_(A))rarr P`
`3.00 = (n_(A))/(10) 10 rArr n_(A) = 3.00`
Similarly, `n_(B) = 1.00`
`n_(C) = (n_(A) + n_(B) + n_(C)) - (n_(A) + n_(B))`
`= 10-(3 + 1) = 6`
Mass of gas `C = n_(C) xx` Mol. mass of C
`= 6 xx 2 = 12`
`n = (2.8)/(28) = 0.1`