Which one of the following pairs of substances on reaction will not evolve H2 gas?
Iron and H2SO4 (aqueous)
Iron and Steam
Copper and HCl (aqueous)
Sodium and Ethyl alcohol
Without losing its concentration ZnCl2 solution cannot be kept in contact with
Au
Al
Pb
Ag
Standard reduction potentials at 25oC of Li+ / Li, Ba2+ / Ba, Na+ / Na and Mg2+ / Mg are -3.05, -2.90, -2.71 and -2.37 volt respectively. Which one of the following is the strongest oxidizing agent?
Mg2+
Ba2+
Na+
Li+
Reduction potential for the following half-cell reactions are
+ 0.32 V
- 0.32 V
+ 1.20 V
- 1.20 V
On heating one end of a piece of a metal, the other end becomes hot because of
Energized electrons moving to the other end
Resistance of the metal
Mobility of atoms in the metal
Minor perturbation cell in the energy of atoms .
The specific conductance of a 0.1 N KCl solution at 23o C is 0.012 ohm-1 cm-1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be
0.142 cm-1
0.66 cm-1
0.918 cm-1
1.12 cm-1
Equivalent conductance of NaCl, HCl and C2H5COONa at infinite dilution are 126.45, 426.16 and 91 ohm-1 cm2, respectively. The equivalent conductance of C2H5COOH is
201.28 ohm-1 cm2
390.71 ohm-1 cm2
698.28 ohm-1 cm2
540.48 ohm-1 cm2
An electrochemical cell is shown below
Pt, H2 (1 atm) |HCl (0.1 M)| CH3COOH (0.1 M)| H2 (1 atm), Pt. the emf of the cell will not be zero, because
emf depends on molarities of acids used
pH of 0.1 M HCl and 0.1 M CH3COOH is not same
The temperature is constant
Acids used in two compartments are different
The equivalent conductance of Ba2+ and Cl- are 127 and 76 ohm-1 cm-1 eq-1 respectively at infinite dilution. The equivalent conductance of BaCl2 at infinite dilution will be
139.52
203
279
101.5
