Question

Calculate the concentration of `K^(o+)` (x) and `Cl^(ɵ)` (y) in a solution obtained by mixing 20 " mL of " 0.1 M `NaCl`, 30 " mL of " 0.2 M KCl, and 25 " mL of " 0.15 M `KNO_3` and making the solution up to 100 mL.
(a). `x=0.06,y=0.0375`
(b). `x=0.0975, y=0.08`
(c). `x=0.08,y=0.08`
(d). `x=0.08,y=0.0375`

Answer 1

(1). 20 " mL of " 0.1 M `NaCl-=2" mmol of " Na^(o+)+2"m mol of "Cl^(ɵ)`
(2). `30" mL of " 0.2 M KCl-=6" m mol of "Na^(o+)+6 "m mol of "Cl^(ɵ)`
(3). `25 " mL of " 0.15 M KNO_3l-=3.7 "m mol of "K^(o+)+3.75" m mol of "Cl^(ɵ)`
(4). Total `-=9.75 " mmol of " K^(o+)+8" m mol of "Cl^(ɵ)+2" m mol of "Na^(o+)+3.75 "m mol of "NO_3^(ɵ)`
Total volume `=100mL`
`x=[K^(o+)]=(9.75)/(100)=0.0975M`
`y=[Cl^(ɵ)]=(8)/(100)=0.08M`
The answer is (b).