Engineering Chemistry Multiple Choice Questions on “Conductivity”.
1. Conductivity is defined as the ability to carry ____________
a) Voltage
b) Resistance
c) Current
d) All of the mentioned
Answer: c
Clarification: Conductivity is defined as the ability to carry current. It is measured by the flow of electrons and charges through a conductor.
2. The reciprocal of conductivity is ____________
a) Viscosity
b) Resistivity
c) Turbidity
d) None of the mentioned
Answer: b
Clarification: The reciprocal of conductivity is resistivity. It is the measure of resistance provided in the path of electrons.
3. Which of the following is a specific conductivity reagent?
a) KCl
b) HCl
c) NaCl
d) MgCl2
Answer: a
Clarification: KCl is a specific conductivity reagent. Specific conductance is a measure of the electric current in the water sampled carried by the ionized substances.
4. The internationally recommended unit for conductance is ____________
a) Poise
b) Dyne
c) Ohm
d) Siemens
Answer: d
Clarification: The internationally recommended unit for conductance is Siemens (S). 1 siemen = 1 ohm-1
5. The cell constant is defined as the ratio of ____________
a) Area of either electrodes to the length between the electrodes
b) Length between the electrodes to the area of either electrodes
c) Length between the electrodes to the volume of either electrode
d) Resistivity to conductivity
Answer: b
Clarification: The cell constant is defined as the ratio of length between the electrodes to the area of either electrodes. It only depends upon the physical dimension of the cell.
6. Choose the correct order of molar ionic conductivities of the following ions.
a) Li+ < Na+ < K+ < Rb+
b) Li+ < K+ < Rb+ < Na+
c) Li+ < Na+ < Rb+ < K+
d) Li+ < Rb+ < Na+ < K+
Answer: a
Clarification: the correct order of molar ionic conductivity is- Li+ < Na+ < K+ < Rb+.
7. On which factor does the conductance of electrolytic solutions depend?
a) Temperature and pressure
b) Number of charge carriers
c) Dielectric constant of the solvent
d) All of the mentioned
Answer: d
Clarification: The factors on which conductance of electrolytic solution depends are- Temperature, pressure, number of charge carriers and dielectric constant of the solvent.
8. On dilution, the specific conductance ____________
a) Increases
b) Remains same
c) Decreases
d) None of the mentioned
Answer: c
Clarification: On dilution, the specific conductance decreases because dilution decreases the concentration of the solution.
9. The equivalent conductance of 0.1 H2SO4offering a resistance of 50ohms when placed in a conductivity cell whose electrodes are 1cm apart with a cross-sectional area of 2cm2 at 250C is?
a) 100 S cm2 eq-1
b) 1000 S cm2 eq-1
c) 10 S cm2 eq-1
d) 1 S cm2 eq-1
Answer: a
Clarification: The equivalent molar conductance is 100 S cm2 eq-1.
Conductivity = Conductance * cell constant
Cell constant = Length / Area
10. Dilution means an increase in the amount of ____________
a) Solute
b) Solvent
c) Electrolyte
d) All of the mentioned
Answer: b
Clarification: Dilution means an increase in the amount of solvent and hence it decreases the concentration of solute particles.