Activation energy (Ea) and rate constants (k1 and k2) of chemical reaction at two different temperatures (T1 and T2) are related by
Standard reduction potentials of the half-reactions are given below.
F2 (g) +2e- → 2F- (aq) ; Eo = +2.85 V
Cl2 (g) +2e- →2Cl- (aq) ; Eo = +1.36V
Br2 (l) +2e- → 2Br- (aq) ; Eo = +1.06 V
I2 (s) +2e- →2I- (aq); Eo = +0.53 V
The strongest oxidising and reducing agents respectively are
F2 and I-
Br2 and Cl-
Cl2 and Br-
Cl2 and Br-
Vapour pressure of chloroform (CHCl3) and dichloromethane (CH2Cl2) at 25oC are 200 mmHg and 41.5 mmHg respectively, Vapour pressure of the solution obtained by mixing 25.5 g of CHCl3 and 40 g of CH2Cl2 at the same temperature will be
(molecular mass of CHCl3= 119.5 u and molecular mass of CH2Cl2 = 85 u)
173.9 mmHg
615.0 mmHg
347.9 mmHg
347.9 mmHg
Molar conductivities (Λom) at infinite dilution of NaCl, HCl and CH3COONa are 126.4, 425.9 and 91.0 S Cm2 mol-1 respectively. Λom for CH3COOH will be
425.5 S cm2 mol-1
180.5 S cm2 mol-1
290.8 S cm2 mol-1
290.8 S cm2 mol-1
Which one of the following does not correctly represent the correct order of the property indicated aginst it?
Ti < V<Cr< Mn: increasing number of oxidation states
Ti< V<Cr3+<Mn3+ : increasing magnetic moment
Ti < V < Cr < Mn : Increasing melting points
Ti < V < Cr < Mn : Increasing melting points
Four successive members of the first series of the transition metals are listed below. For which one of them, the standard potential value has a positive sign?
Co (Z=27)
Ni (Z=28)
Cu (Z=29)
Cu (Z=29)
In Which of the following arrangement, the given sequence is not strictly according to the property indicated against it ?
HF < HCl< HBr < HI : increasing acidic strength
H2O < H2S < H2Se < H2Te : increasing pKa values.
NH3 < PH3 < AsH3 < SbH3 : increasing acidic character
NH3 < PH3 < AsH3 < SbH3 : increasing acidic character
B.
H2O < H2S < H2Se < H2Te : increasing pKa values.
(a,c) As we move from top to bottom in a group, the acidic strength of hydrides increases. Therefore, order of acidic strength of hydrides of VA and VII A group elements is
NH3 < PH3 < AsH3< SbH3
HF<HCl < HBr <HI
The catalytic activity of transition metals and their compounds is ascribed mainly to
their magnetic behaviour
their unfilled d- orbitals
their ability to adopt variable oxidation states
their ability to adopt variable oxidation states
The Gibb's energy for the decomposition of Al2O3 at 500o C is as follow
2/3 Al2O3 → 4/3 Al + O2;
ΔrG = +960 kJ mol-1
The potential difference needed for the electrolytic reduction aluminium oxide (Al2O3) at 5000 C is at least
4.5 V
3.0 V
2.5 V
2.5 V