The compound whose aqueous solution has the highest pH is
NaCl
NaHCO3
Na2CO3
NH4 Cl
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
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)
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%
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
Aqueous solution of acetic acid contains
CH3COO- and H+
CH3COO-, H3O+ and CH3COOH
CH3COO-, H3O+ and H+
CH3 COOH, CH3COO- and H+H3COOH
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
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
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)
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
