Home
Class 12
CHEMISTRY
Two buffer, (X) and (Y) of pH 4.0 and 6....

Two buffer, (X) and (Y) of pH `4.0` and `6.0` respectively are prepared from acid HA and the salt NaA. Both the buffers are `0.50` M in HA. What would be the pH of the solution obtained by mixing equal volumes of the two buffers ? `(K_(HA)=1.0xx10^(-5))`

Text Solution

Verified by Experts

The correct Answer is:
5.7033
pH of buffer is given by
`pH=-logK_(a) + "log"(["conjugate base"])/0.5`
For I: `4=-log10^(5) + "log"(["conjugate base"])/0.5`
[conjugate base]=0.05M=[Salt]
For II: `6= -log10^(-5) +"log"(["conjugate base"])/0.5`
[conjugate base]= [Salt]= 5M
Now the two buffers[(I:NaA=0.05M and HA=0.5M) and ( II:NaA=5M and HA=0.5M)]
Are mixed in equal proportion.
Thus, new conc. of NaA in mixed buffer` =((0.05)xxV+(5xxV))/(2V) =5.05/2 M`
New conc. of HA in mixed buffer `=(0.5V + 0.5V)/(2V)=0.5M`
Thus,`pH=-log10^(-5) + "log"5.05/(2xx0.5)=5+0.7033=5.7033`
Promotional Banner

Similar Questions

Explore conceptually related problems

Find the pH of a buffer solution having equal volumes of 0.2MNH_(4)OH and 0.2M NH_(4)Cl (K_(b) for base =1.0xx10^(-5) )

A buffer solution with pH 9 is to be prepared by mixing NH_(4)OH solution . K_(b) =1.8 xx 10^(-5).

10 ml of 0.2 M acid is added to 250 ml of a buffer solution with pH = 6.34 and the pH of the solution becomes 6.32 . The buffer capacity of the solution is :

When 0.2 mole of an acid is added to 4 lit of a buffer solution, the P^(H) of the buffer decreases by 0.5 . What is the buffer capacity of the solution.?

When 0.1 mole of an acid is added to 2 L of a buffer solution, the P^(H) of the buffer decreases by 0.5 . The buffer capacity of the solution is

A weak acid HA has K_(a) = 10^(-6) . What would be the molar ratio of this acid and its salt with strong base so that pH of the buffer solution is 5 ?