The pH value of a 10 m solution of HCl is
less than 0
Equal to 0
Equal to 1
Equal to 2
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 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
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
A weak acid HA, has a Ka of 1.00 ×10-5. If 0.100 mole of this acid is dissolved in one litre of water, the percentage of acid dissociated at equilibrium is closest to
99.0%
1.00 %
99.9%
0.100%
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 concentration of [H+] and concentration of [OH- ] of a 0.1M aqueous solution of 2% ionised weak monobasic acid is [ionic product of water = 1×10-14 ]
0.02×10-3 M and 5×10-11 M
1×10-3 M and 3×10-11 M
2×10-3 M and 5×10-12 M
3×10-2 M and 4×10-13 M
The compound whose aqueous solution has the highest pH is
NaCl
NaHCO3
Na2CO3
NH4 Cl
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
Which of the following molecules acts as a Lewis acid ?
(CH3)3B
(CH3)2O
(CH3)3P
(CH3)3N