Quick Revision: Chemical Effects of Electric Current Video Lecture | Science Class 8

0:0:0: hello everyone today we're going to
0:0:2: learn about the chemical effects of
0:0:4: electric current let's start with
0:0:6: understanding what electrical conduction
0:0:8: means electrical conduction is the
0:0:11: movement of electrically charged
0:0:13: particles through a material this
0:0:15: movement can create an electric
0:0:18: current now let's talk about conductors
0:0:21: and
0:0:22: insulators conductors are materials that
0:0:24: allow charges to flow freely for example
0:0:28: a silver spoon is a condu conductor
0:0:31: insulators on the other hand resist the
0:0:33: free movement of charges a rubber
0:0:36: balloon or a rubber tire is an insulator
0:0:40: a copper wire is a conductor while a
0:0:42: diamond is an insulator we can divide
0:0:45: conductors into good conductors and bad
0:0:48: conductors bad conductors are substances
0:0:51: that allow electric current to pass
0:0:53: through them but in very little amount
0:0:56: examples are rubber and paper good
0:0:59: conductors are substances that allow
0:1:1: electric current to pass through them
0:1:3: easily gold and a silver spoon are good
0:1:5: conductors of
0:1:7: electricity now let's talk about liquids
0:1:10: and their ability to conduct electricity
0:1:12: do you think pure water conducts
0:1:14: electricity if you answer yes you are
0:1:17: wrong pure distilled water does not
0:1:20: conduct
0:1:21: electricity so what can make water
0:1:24: conductive water with salt dissolved in
0:1:26: them can carry
0:1:28: electricity we can check that this by
0:1:30: this experiment using two electrodes and
0:1:32: a light bulb but first of all what are
0:1:35: electrode electrodes are conducting
0:1:37: materials through which current enters
0:1:40: or leaves a substance the positive
0:1:42: electrode is connected to the positive
0:1:45: terminal of the battery it is also known
0:1:47: as the anode the negative electrode is
0:1:50: connected to the negative terminal of
0:1:52: the battery it is also known as the
0:1:56: cathode now let's come back to our
0:1:59: experiment
0:2:0: when electric current is passed through
0:2:2: this salty water some chemical reaction
0:2:5: takes place this is known as the
0:2:7: chemical effects of electric current
0:2:10: here's what we can observe salts
0:2:12: dissolved in water are responsible for
0:2:14: conduction of electricity through water
0:2:17: tap water acid Solutions basic Solutions
0:2:20: Etc are good conductors of electricity
0:2:24: but pure distilled water is a poor
0:2:26: conductor of electricity because no salt
0:2:29: is present in distilled
0:2:31: water here are some examples of the
0:2:33: chemical effects of electric current
0:2:36: when electric current is passed through
0:2:38: water water dissociates into hydrogen
0:2:41: and oxygen hydrogen is deposited over
0:2:45: the negative pole and oxygen is
0:2:47: deposited over the positive pole when
0:2:50: electric current is passed through the
0:2:52: solution of a metal salt such as copper
0:2:55: sulfate the metal gets deposited at the
0:2:58: negative pole because the metal metal is
0:3:0: positively
0:3:1: charged electroplating is one of the
0:3:4: chemical effects of electric current it
0:3:7: is a chemical process using which a
0:3:9: metal is coated with a layer of another
0:3:11: desired metal electroplating is done to
0:3:15: prevent iron from getting rusted here's
0:3:17: how the process of electroplating Works
0:3:21: a metal salt solution is taken in a
0:3:23: container the salt of the metal is
0:3:25: chosen which is to be coated over
0:3:28: another metal the metal which is to be
0:3:30: coated is dipped in the solution and
0:3:33: connected with the negative pole the
0:3:36: metal for the desired coating is
0:3:38: connected with the Positive pole when
0:3:41: electric current is passed through the
0:3:43: solution the metal from the anode is
0:3:45: dissolved in the salt solution and
0:3:48: deposited over the negative Pole or
0:3:51: cathode thus a coating of the desired
0:3:54: metal is obtained on another metal
0:3:57: electroplating has many uses water pipes
0:4:0: made of iron are coated with a layer of
0:4:3: zinc metal by
0:4:4: electroplating zinc is less reactive
0:4:6: than iron and prevents the iron pipe
0:4:9: from getting rusted rims of wheels of
0:4:11: Cycles cars Etc are electroplated with
0:4:15: chromium metal the layer of chromium
0:4:17: metal gives them a shiny appearance and
0:4:19: prevents rust ornaments made of silver
0:4:22: or other cheap metals are electroplated
0:4:25: with gold to give them the appearance of
0:4:27: gold that's it for today's lesson on the
0:4:30: chemical effects of electric current we
0:4:33: hope that you have understood the topic
0:4:35: you can now study chapter notes watch
0:4:38: video lectures and solve McQ tests of
0:4:40: this chapter on edurev to ensure you
0:4:42: score well in your school exams and
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0:4:51: and much more for Class 8 thank you