Heating & Chemical Effect of Current

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What is the thermoelectric potential developed by a single thermocouple when the temperature difference between the hot and cold junctions is 20 K?

40 μV (correct)

20 μV

10 μV

80 μV

What occurs at the junction where current flows from Cu to Fe?

Energy is released

Energy is absorbed (correct)

No energy transfer occurs

The temperature remains constant

What is the total emf developed by a thermopile consisting of 150 thermocouples in series when the temperature difference between the hot and cold junctions is 20 K?

80 mV

120 mV (correct)

144 mV

150 mV

What is the relationship between the heat absorbed or liberated at a junction and the charge passing through it?

H ∝ Q Signup and view all the answers

What is the process of decomposition of an electrolyte solution into ions on passing an electric current through it?

Electrolysis Signup and view all the answers

What is the unit of the Peltier coefficient?

J/C Signup and view all the answers

What is the term for the ability of an electric current to produce or speed up chemical change?

Chemical effect Signup and view all the answers

What determines the value of the Peltier coefficient?

Both the temperature of the junction and the difference in electron density of the two metals Signup and view all the answers

What is the term for liquids that do not allow current to pass through them?

Insulators Signup and view all the answers

What is the relationship between the Peltier coefficient and the absolute temperature?

π = T × S Signup and view all the answers

What is the graph of thermo electric power in a thermocouple?

A straight line with a positive slope Signup and view all the answers

What happens when a positive charge flows from a high potential to a low potential?

Energy is released Signup and view all the answers

What is the polarity of the contact potential at each junction in an iron-copper thermocouple?

Iron is at higher potential Signup and view all the answers

What happens at the junction in a thermocouple when current flows from iron to copper?

Heat is evolved Signup and view all the answers

What is the Peltier effect?

Heat evolved or absorbed at a junction of two different metals when a current is passed through it Signup and view all the answers

What is the primary purpose of electroplating?

To make the base metal look more attractive Signup and view all the answers

What is the role of the anode in electrolysis?

It is the site of oxidation Signup and view all the answers

What is the equivalent weight of an element?

The ratio of the atomic weight of an element to its valency Signup and view all the answers

What is the purpose of a voltameter?

To carry out electrolysis Signup and view all the answers

What is the term for the decomposition of an electrolyte solution into ions on passing an electric current through it?

Electrolysis Signup and view all the answers

What is the volume ratio of hydrogen and oxygen liberated during electrolysis of water?

2:1 Signup and view all the answers

What is the relationship between the mass of substance deposited at the cathode and the quantity of electricity passed through the electrolyte?

Directly proportional Signup and view all the answers

What is the electrochemical equivalent of a substance?

The mass of substance deposited at the cathode when one coulomb of charge passes through the electrolyte Signup and view all the answers

What occurs at the cathode during electrolysis of water?

Hydrogen gas is collected Signup and view all the answers

What is the role of the anode in electrolysis of water?

To collect oxygen gas Signup and view all the answers

What is the primary reason for the wastage of Zn in a voltaic cell?

Local electric currents due to impurities on the surface of the Zn rod Signup and view all the answers

What is the purpose of amalgamating the Zn rod with mercury?

To prevent local electric currents and wastage of Zn Signup and view all the answers