The percentage degree of hydrolysis of a salt of weak acid (HA) and weak base (BOH) in its 0.1 M solution is found to be 10%. If the molarity of the solution is 0.05 M, the percentage hydrolysis of the salt should be :
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] Useful buffer range of weak acid HA(K_(a)=10^(-5)) is :
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 )
pH of solutions of four sodium salts NaW, NaX, NaX, NaY and NaZ were found to be 7.0, 9.0, 10.0 and 11.0 respectively. If each solution has concentration 0.1 M, the weakest acid is :
Arrhenius studies the effect of temperature on the rate of a reaction and postulted that rate constant varies with temperature exponentially as k=Ae^(E_(a)//RT) . Thuis method is generally used for finding the activation energy of a reaction. Keeping temperature constant, the effect of catalyst on the activation energy has also been studied. If the rate of reaction doubles for 10^(@)C rise of temperature form 290K to 300K, the activation energy of the reaction will be approximately: a) 40 Kcal mol^(-1) b) 12 Kcal mol^(-1) c) 60 Kcal mol^(-1) d) 70 Kcal mol^(-1)
phenol associates in benzene to a certain extent in dimerisation reaction. A solution containing 0.02 kg of phenol in 1.0 kg of benzene has its freezing point depressed 0.69 k. Hence, the degree of association of phenol demerized will be, [ K_(f)(C_(6)H_(6)) =5.12 k "mol"^(-1) ] a) 0.63 b) 0.73 c) 0.83 d) 0.93
A 1 litre solution containing NH_(4)Cl and NH_(4)OH has hydroxide ion ion concentration of 10^-6) mol//litre. Which of the following hydroxides could be precipitated when the solution is added to 1 litre solution of 0.1 M metal ions? (I) Ba(OH)_(2)(K_(sp)=5xx10^(-3)) , (II) Ni(OH)_(2)(K_(sp)=1.6xx10^(-16)) (III) Mn(OH)_(2) (K_(sp)=2xx10^(-13)) , (IV) Fe(OH)_(2) (K_(sp)=8xx10^(-16))
1.0 g of a monobassic acid HA in 100 g water lowers the freezing point by 0.155 K. IF 0.75 g, of same acid requires 25 mL of N/5 NaOH solution for complete neutralisation then %, degree of ionization of acid is ( K_(f) of H_(2)O = 1.86 K kg "mol"^(-1) ):
What will be the pH and % alpha ( degree of hydrolysis ) respectively for the salt BA of 0.1M concentration ? Given : K_(a) for HA=10^(-6) and K_(b) for BOH=10^(-6)
NARENDRA AWASTHI-IONIC EEQUILIBRIUM-Assertin-Reason Type Questions
