The dissociation equilibrium of a gas AB2 can be represented as : 2AB2(g) 2AB(g) +B2(g).The degree of dissociation is 'x' and is small compared to 1.The expression relating the degree of dissociation (x) with equilibrium constant Kp and total pressure p is
(2Kp/ p)
(2Kp / p)1/3
(2Kp / p)1/2
(Kp / p)
The solubility product of CuS ,CdS and HgS are 10-31 , 10-44 , 10-54 , respectively.The solubility of these sulphides are in the order .
CdS > HgS > CuS
HgS > CdS > CuS
CdS > CuS > HgS
CuS > CdS >HgS
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 solubility of a saturated solution of calcium fluoride is 2×10-4 mol / L . Its solubility product is
12×10-2
14×10-4
22×10-11
32×10-12
Which of the following statements about pH and H+ ion concentration is incorrect ?
addition of one drop of concentrated HCl in NH4OH solution decreases pH of the solution.
A solution of the mixture of one equivalent of each of CH3COOH and NaOH has a pH of 7 .
pH of pure neutral water is not zero .
A cold and con.H2SO4 has lower H+ ion concentration than a dilute solution of H2SO4
The hydride ion H- is strong base than its hydroxide ion OH-. Which of the following reactions will occur if sodium hydride (NaH) is dissolved in water ?
2H-(aq) + H2O(l)→H2O+H2 +2e-
H-(aq) + H2O(l)→OH-+H2
H - + H2O(l) → no reaction
None of the above
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
H2S gas when passed through a solution of cations containing HCl precipitates the cations of second group in qualitative analysis but not those belonging to the fourth group. It is because
Presence of HCl decreases the sulphide ion concentration.
Presence of HCl increases the sulphide ion concentration.
Solubility product of group 2nd sulphides is more than that of group iv sulphides
Sulphides of group iv cations are unstable in HCl
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)
In which of the following the solubility of AgCl will be minimum ?
0.1 m NaNO3
Water
0.1 m NaCl
0.1 m NaBr
