Question

A mixture contains `F` and `Cl` atoms . The removal of an electron form each atom of the sample requires `28 kJ` while addition of an electron to each atom of mixture releases `68.8 kJ` energy .Calcualte the % composition of mixture .Given `IE` per atoms for `F` and `Cl` are `27.91 xx10^(-22)kJ` and `20.77 xx10^(-22) kJ`.
Electron gain enthaply for F and Cl are ` -5. 31 xx10 ^(-22) kJ` and `-5.78 xx 10^(22) kJ` respectivley

Answer 1

Let a atoms of F and b atoms of `Cl.`
`27. 91 xx 10^(22 ) xx a + 20. 77xx 10^(27) xx b= 284` ….(1)
` 5.52 xx10^(22) xxa+5.78 xx10^(-22)xxx b= 68.8 `….(2)
By eqs . (1)and (2) ,
` a =4.6 xx 10^(22) , b =7.5 xx10^(22)`
or ` %a =(4.6 xx10^(22))/((4.6+7.5)xx10^(22)) xx100 =38%`
`:. % b=62 %`