An acid base indicator (K_(a) =10^(-5)) has its pH range 4.4 - 6.0. The correct statement (s)amongst the following is/are

An acid base indicator (K_(a) =10^(-5)) has its pH range 4.4 - 6.0. Th

1.	An acid base indicator (K_(a) =10^(-5)) has its pH range 4.4 - 6.0. The correct statement (s)amongst the following is/are
Answer» The indicator will be suitable for the titration of a strong acid against a weak base. The acidic colour of the indicator wil predominate if the concentration of acidic FORM is 4 times more than that of the basic form. The indicator will be suitable for the titration of weak acid against a strong base. The basic colour of the indicator will prevail when concentration of basic form will be at LEAST 10 times more than that of the acidic form. Solution :pH range ` lt7 rArr ` good for weak base (b)Acid colour dominate if pH ` lt 4.4 ` ` i.e. pK_(In)+log ""( In^(-))/(HIN) lt 4.4 ` `rArr log ""(In^(-))/(HIn) lt 4.4 -5=-0.6` ( c )basic colour will dominate if ` pH gt 6` ` rArr PK _(In)+log ""(I_n^(-) ) /(HIn)gt 6` `rArr log ""( I_n^(-))/( HIn)gt 6-5=1 rArr (I_n^(-))/(HIn) gt 10 `