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
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
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 Strongest conjugate base is ____ .
NO3-
Cl-
SO4 2-
CH3COO-
The solubility product of a sparingly soluble salt AX2 is 3.2 ×10-11. Its solubility ( in mol / L ) is _____ .
5.6 ×10-6
3.1 ×10-4
2 ×10-4
4 ×10-4
Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H+ ion concentration in the mixture ?
1.11×10-4 M
3.7×10-4 M
3.7×10-3 M
1.11×10-3 M
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 silphides
Sulphides of group iv cations are unstable in HCl
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
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 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
