Which of the following salt does not get hydrolysed in water ?
KClO4
NH4Cl
CH3COONa
None of these
A.
KClO4
Only salts of (weak acid + strong base) and (strong acid + weak base) get hydrolysed (i.e., show alkalinity or acidity in water) . KClO4 is a salt of strong acid and strong base ,therefore it does not get hydrolysed in water .
KClO4 K+ + ClO4-
H2O
KI and CuSO4 solution when mixed , give :
CuI2 + K2SO4
Cu2I2 + K2SO4
K2SO4 + Cu2I2 + I2
K2SO4 + CuI2 + I2
C.
K2SO4 + Cu2I2 + I2
2KI + CuSO4 + K2SO4
2CuI2 Cu2I2 + I2
Hence , solution contains K2SO4 + Cu2I2 + I2
Which among the following elements have lowest value of IE1 ?
Pb
Sn
Si
C
B.
Sn
The ionisation energy of Tin (Sn) is less than that of lead (Pb) .It is due to the poor sheilding of d - and f - electron in Pb due to which it feels greater attraction from nucleus .
Which of the following element is a metalloid ?
Bi
Sn
Ge
C
C.
Ge
Boron (B) , Si , Ge , As , Sb , Te and At are the metalloid elements .Bismuth (Bi) and tin (Sn) are metals while carbon (C) is non-metal .
What will be the pH value of 0.05 M Ba(OH)2 solution ?
12
13
1
12.96
B.
13
0.05 M Ba(OH)2 Solution
= 2 x 0.05 N Ba(OH)2
= 0.10 N Ba(OH)2
pOH = -log [OH-]
= - log (0.10) = 1
pH = 14 - pOH
= 14 - 1 = 13
In the reaction :
H2 + I2 2HI
In a 2 litre flask 0.4 moles of each H2 and I2 are taken .At equilibrium 0.5 moles of HI are formed .What will be the value of equilibrium constant ,Kc ?
20.2
25.4
0.284
11.11
D.
11.11
H2 | + | I2 | 2HI | ||
0.4 | 0.4 | 0.50 | |||
At equilibrium | 0.4- 0.25 | 0.4 - 0.25 | 0.50 | ||
= 0.15 | = 0.15 |
Which of the following elements never show positive oxidation number ?
O
Fe
Ga
F
D.
F
Fluorine is the most electronegative element in the periodic table so it never shows positive oxidation state .
Ionisation depends upon :
pressure
volume
dilution
none of these
C.
dilution
Ionisation depends upon concentration , temperature , nature of solute and on nature of solvent .Ionisation increases on increasing dilution .
The first ionisation potential is maximum for :
B
N
O
Be
B.
N
Ionisation potential generally increase when we move in a period from left to right but IE1 of N2 is greater than that of O2 .It is due to the more stable (half-filled orbitals) configurations of N .
The solubility of in water is Sb2S3 in water is 1.0 x 10-5 mol/litre at 298 K .What will be its solubility product ?
108 x 10-25
1.0 x 10-25
144 x 10-25
126 x 10-25
A.
108 x 10-25
+
Solubility product
(Ksp) = [Sb3+]2 [S2]3
= (2s)2 (3s)3
= 108 s5
= 109 x (1.0 x 10-5)5
= 108 x 10-25
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