The rapid change of pH near the stoichiometric point of an acid base titration is the basis of indicator detection. pH of the solution is related to ratio of the concentrations of the conjugate acid (HIn) and base (In-) forms of the indicator given by the expression
log [In-] / [HIn] = pKIn-pH
log [HIn] / [In-] = pKIn-pH
log [HIn] / [In-] = pH-pKIn
log [In-] / [HIn] = pH -pKIn
A Physician wishes to prepare a buffer solution at pH =3.58 that efficiently resist changes in pH yet contains only small concentration of the buffering agents. Which one of the following weak acid together with its sodium salt would be best to use ?
m-chlorobenzoic acid (pKa=3.98)
P-Chlorocinnamic acid(pKa = 4.41)
2,5 -dihydroxy benzoic acid (pKa=2.97)
Acetoacetic acid(pKa=3.58)
The pH value of blood does not change appreciably by a small addition of an acid or base ,because the blood -
is a body fluid
can be easily coagulated
contains iron as a part of the molecule
contains serum protein that acts as buffer
Which of the following is most soluble ?
Bi2S3(KSP=1×10-70)
MnS(KSP=7×10-16)
CuS(KSP=8×10-37)
Ag2S(KSP=6×10-51)
What is the [OH-] in the final solution prepared by mixing 20.0 mL of 0.050 M HCl with 30.0 mL of 0.10 M Ba(OH)2?
0.10 M
0.40 M
0.0050 M
0.12 M
Calculate the pOH of a solution at 250C that contains 1.0×10-6 M of hydronium ions .
7.00
4.00
9.00
1.00
The values of Kp1 and Kp2 for the reactions and are in ratio of 9:1.If degree of dissociation of x and A be equal, then total pressure at equilibrium (i) and (ii) are in the ratio .
3:1
1:9
36:1
1:1
Aqueous solution of acetic acid contains-
CH3COO- and H+
CH3COO-, H3O+ and CH3COOH
CH3COO-, H3O+ and H+
CH3 COOH, CH3COO- and H+
Solution of 0.1 N NH4OH and 0.1 N NH4Cl has pH 9.25, then find out pKb of NH4OH
9.25
4.75
3.75
8.25
The hydrogen ion concentration of a 10-8 M HCl aqueous solution at 298k (kw = 10-14 ) is ___________ .
1.0×10-6 M
1.0525×10-7 M
9.525×10-8 M
1.0×10-8 M
