Question

Calculate the pH of an aqueous solution of 16 mL of 0.00046 M HClO4(aq) after dilution to 42 mL.

Answer 1

1000
`cm^(3)` of HClO_{4} [/tex] contain 0.00046mol
16
`cm^(3)` of HClO_{4} [/tex] contain x
x =
`(16cm ^(3) * 0.00046mol)/(1000cm x^(3) )`
x = 0.00000736mol



`M_(1) V_(1) = M_(2) V_(2)`
(0.00000736mol)(16
`cm^(3)`)=
`(x) (42cm^(2))`

`x= ((0.00000736mol) * (16cm^(3)) )/(42cm^(3) )`
= 0.000002803mol


pH= -log [
`H^(+)`]
= -log (0.000002803cm
`^(3)`
= 5.55