100 ml solution having 0.2 M HA (weak acid, K_(a), = 1.0x10^(-5) ) and 0.2 N NaA, 200 ml of 0.1 M NaOH has been added. Furthermore, diluted to IL. Which of the following statement is correct?

100 ml solution having 0.2 M HA (weak acid, K_(a), = 1.0x10^(-5) ) and

1.	100 ml solution having 0.2 M HA (weak acid, K_(a), = 1.0x10^(-5) ) and 0.2 N NaA, 200 ml of 0.1 M NaOH has been added. Furthermore, diluted to IL. Which of the following statement is correct?
Answer» Initially , the SOLUTION has pH equal to 5, that is before additions of NaOH In the final solution , the CONCENTRATION of `[OH^(-) ] is 10^(-9) ` M. After the addition of NaOH , the pH of solution increase by four units. After the addition of base, the solution losses buffering action and can be restored after the addition of acid. Solution :Initially acid buffer is present ` pH =5+ LOG ""(0.2)/( 0.2)= 5` (b)after dilution to1 LT, ` [HA] =0.02 N, [NaA ]= 0.02 N` ` [NaOH ]=0.02 N` ` {:( NaOH +, HA to , NaA + H_2O) , (0.02 N , 0.02N , -),( -,-,0.02N):}` ` therefore` Due to addition of NaOH , buffer disappeared & salt is formed ` pH =7+ ( 5)/(2) +(1)/(2) log (4 XX 10 ^(-2)) = 8.8 `