Solution of a weak acid and its anion (that is,its conjugate base) or of a base and its common cation are buffered. When we add a small amount of acid or base to any one of the, the pH of solution change very little. pH of buffer solution can be computed as for acidic buffer : pH=pK_(a)+ log.(["Conjugate base"])/(["Acid"]) for basic buffer : pOH=pK_(b)+log.(["Conjugate acid"])/([Base]) It is generly accepted that a has useful buffer cpacity (pH change resisting power) provided that the value of [salt or conjugate base] /[acid] for acidic buffer lies within the range of 1 : 10 to 1. Buffer capacity is maximum when [conjugate base] = [acid] Calculater the pH of a solution made by adding 0.01 mole of HCl in 100 mL of a solution which is 0.2 M in NH_(3)(pK_(b)=4.74) and 0.3 M in NH_(4)^(+) : (Assuming no change in volume )
A Galvanic cell consits of three compartment as shown in figure. The first compartment contain ZnSO_4 (1M) and III compartment contain CuSO_4 (1M). The mid compartment contain NaNO_3 (1M). Each compartment contain 1L solution: E_(Zn^(2+)//Zn)^(@)=-0.76 , E_(Cu^(2+)//Cu)^(@)=+0.34 , The concertation of Zn^(2+) in first compartment after passage of 0.1 F charge will be:
A cell of e.m.f. 4 V and of negligible internal resistance is connected in series with a potentiometer wire of length 400 cm. The e.m.f. of a Leelanche cell is found to be balacned at 150 cm from the positive end of the potentiometer wire. What is the e.m.f. of the Leclanche cell ?
With a certain cell, the balance point is obtained at 65 cm from the zero end of a potentiometer wire. With another cell, whose e.m.f. is less than that of the first by 0.1 V, the balance point is obtained at 60 cm. What is the e.m.f. of the first cell ?
The resistance of a conductivity cell containing 10^-3 M KCI solution at 25^@ C is 1500 Omega . What is the cell constant If conductivity of 10^@ M KCl solution at 25^@ C is 1.5 xx 10^-4 S cm^-1 ?
A cell consists of two hydrogen electrodes. The negative electrode is in contact with a solution having pH=6. the positive electrode is in contact with a solution of pH=x. calculate the value of x if the e.m.f of the cell is found to be 0.118V at 298K
A living cell contains a solution which is isotonic with 0.2 M glucose solution. What osmotic pressure develops when the cell is placed in 0.05 M BaCl_(2) solution at 300 K ?
A cell contains two hydrogen electrodes. The negative electrode is in contact with a solution of 10^-6M hydrogen ions. The e.m.f. of the cell is 0.118V at 25^@C . Calculate the concentration of hydrogen when at the positive electrode.
The resistance of a conductivity cell containing 0.001M KCl solution at 298K is 1500 Omega . What is the cell constant ( in mm^(-1) ) if the conductivity of 0.001M KCl solution is 2xx10^(-3)Smm^(-1)
Consider the following half cell reaction: Br_2+2barerarr2Br^- , E^@=1.09V I_2+2barerarr2I^- , E^@=0.54V If I_2 and Br_2 are added to solution containing 1M concentration of I^- and Br^- resepctively. How will the increase in the concentration of Br^- affect E_(cell) ?
