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%
Which of the following molecules acts as a Lewis acid ?
(CH3)3B
(CH3)2O
(CH3)3P
(CH3)3N
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 hydride ion H- is strong base than its hydroxide ion OH-. Which one 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
The Strongest conjugate base is______________
NO3-
Cl-
SO4 2-
CH3COO-
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 one 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)
The pH value of 10 m solution of HCl is_____________
less than 0
Equal to 0
Equal to 1
Equal to 2
The conjugate acid of NH2- is_________________
N2H4
NH4 +
NH2 OH
NH3
In which one of the following the solubility of AgCl will be minimum ?
0.1 m NaNO3
Water
0.1 m NaCl
0.1 m NaBr
