Question

Determine the pH of an HF solution of each of the following concentrations.

HELP PLEASE.

Determine the pH of an HF solution of each of the following concentrations. 5.30x10^-2 Express your answer to two decimal places. Part C 2.00 x 10^-2 M Express your answer to two decimal places.

Answer 1

HF-->H+ + F-

pH=-log[H+]

a.)[H+]=5.3*10^-2

pH=-log[5.3*10^-2]

=1.27 ans

b.) [H+]=2*10^-2

pH=-log[2*10^-2]

=1.69 ans

Answer 2

Ka for HF=[H+]*[F-]/[HF]=7.2*10^-4

As [H+]=[F-]=x and [HF]=5.3*10^-2

therefore x^2/(5.2*10^-2)=7.2*10^-4

x=6.11*10^-3 M

so pH=-log[6.11*10^-3]

=2.21 ans

b.) for [HF]=2*10^-2 M

x=3.79*10^-3 M

pH=-log[H+]

=2.42 ans

Answer 3

pH-1.275-1.28 c) PHlog 2.00 xio) P.689 H. 70