# Suppose it is required to make a buffer solution of pH =4 using acidic acid and sodium acetate.How much of sodium acetate is to be added to one litre of N/10 acidic acid? HInt:disassociation constant of acetic acid=1.8*10^-5 M

1
by tanani1ramyaj8ee

2015-12-16T19:59:13+05:30

### This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.

(Let sodium acetate’s Molarity is M)
Here,                HAc   + H2O  = H3O+  + Ac-

Initial                 0.10                  0          M
Change             -x                     +x        +x
At equilibrium    0.10 – x           + x       M + x
[H3O-] [Ac-]
Now,   Ka  = -----------------
[ HAc]

(x) (M+x)

= -----------------    =   1.8 X 10-5
(0.10 – x)

Now, it comes roughly (x)(M)/(0.10) = 1.8 X 10-5;  -(i)

neglecting x in M+x and 0.10-x;

Here  pH = 4 (given), or x = 10-4,
putting the value of x in eq (i),

We get the value of M = 0.018M

So, sodium acetate required = 1.476 gm per litre
Answer:  1.476 gm in one litre