Page 1 :
GURUKUL CENTRAL ACADMY, CH.- 14. CHEMICAL EFFECTS OF, ELECTRIC CURRENT, WORKSHEET-1, A. 1. b 2. a 3. c 4. a, B. Refer text book C. Refer text book, WORKSHEET-2, Refer text book, , TEXTBOOK EXERCISES, Page 159 Try These, 1. Nucleus, 2. Negative 3. Flow of charged particles, 4. Distilled water, 5. Cation, , EXERCISES, A. 1. b. 2. b. 3. c. 4. c. 5. b. 6. a. 7. b. 8. b., B. 1. current, 2. bad 3. good 4. electrolytes, 5. negative, 6. cathode 7. salt, 8. cathode, 9. electrolytic refining, C. 1. – f., D. 1. T, E. 1., , 2. – d., , 3. – a. 4. – b., , 2. T 3. F 4. T 5. T, , Anion, 4. Light Emitting Diode, , 5. – c., , 6. T, 2. Orbit 3. Conductor, 5. Tin 6. Newton, , 6. – e.
Page 2 :
GURUKUL CENTRAL ACADMY, F. 1., , Kerosene, alcohol, , 2 The occurrence of a chemical reaction by passing electric current, through an electrolyte is called electrolysis., 3., , Electroplating is the process of depositing a layer of any desired, metal on another metal by the process of electrolysis., , 4., , We will dissolve sugar in water., , 5., , Galvanisation is a process of electroplating iron with zinc., , 6., , Because LED glows even when a weak electric current flows, through it., , 7., , To make it look attractive and protect it from corrosion., , 8., , To protect them from corrosion and give the objects a shiny, appearance., , 9., , The flow of charged particles through a substance constitutes the, electric current., , G. 1., , Conduction of electricity through a solution or electrolyte takes, place through ions. When electricity is passed, cations move, towards the cathode and anions move towards the anode. Due to, this circuit gets completed. This movement of ions in the solution, is called electrolytic conduction.
Page 3 :
GURUKUL CENTRAL ACADMY, 2., , The process of depositing a layer of any desired metal, on, another material by means of electricity is called electroplating., Electroplating is done to make articles look attractive and protect, them from corrosion., Uses of electroplating, • Car parts, bicycle handle bars, wheel rims, etc., are electroplated, with chromium to protect them from corrosion and give the, objects a shiny appearance. Sometimes, you may find the buckle, of an old waist belt with black spots. These spots are of iron, metal that shows when the chromium electroplating goes off., • Cans made of iron, used to store food are electroplated with tin., Tin is less reactive than iron. Food stored in it does not come in, contact with iron and thus does not get spoilt., • Iron which is used for making bridges and automobiles is, electroplated with zinc. Zinc protects iron from rusting., , 3., , Refer Activity 5., , 4., , An atom that gains electrons develops a negative charge and forms, a negative which is called anion and the atom that loses electrons,, develops a positive charge and forms a positive ions which is, called cation., , 5., , Refer Activity 6., , 6., , When electric current is passed through a conducting solution, it, causes a chemical reaction to take place. This is a chemical effect, of electric current. For example, salt when dissolved in water,, forms ions – the positive ion (cation) and the negative ion (anion)., Electricity is passed through the solution with the help of rods, called electrodes. Movement of ions in the solution is called, electrolytic or ionic conduction and the process is called, electrolysis. During electrolysis of sodium chloride the following
Page 4 :
GURUKUL CENTRAL ACADMY, reactions take place, NaCl, At cathode : Na+ + e–, At anode, : Cl– – e–, Reaction, 2NaCL, , Na+ + Cl–, Na, Cl, 2Na + Cl, , 2, , Thus we can see a chemical change taking place in the process of, electrolysis., 7., , Cut a potato in two parts and join a conducting wire with a coil and, switch as given in the diagram. The current passes through it. It, shows that current passes through it., , 8. LED is a device which glows when a voltage is supplied. LEDs are, used as indicator lamps in many devices. LED lights up even when, the current in the circuit is very low.
