14.6. Chemical effects of electric current are used widely and one of the effect is electroplating. Question 4. Electroplating … Firemen shuts off the main electrical supply for the area because water is a good conductor of electricity and the firemen can get electrocuted. Electroplating Mention the components of the circuit of tester How will you identify the positive … (Remember to wash and wipe the ends of tester after testing each liquid). Add a little sugar to the distilled water in the third cap and dissolve it. Why? Ans: Uses of electroplating: (i) Chromium is a shiny metal that does not corrode and resists scratches. Performance & security by Cloudflare, Please complete the security check to access. Electroplating on a commercial scale was begun about 1840–41 and was accelerated by the discovery of cyanide solutions for plating silver, gold, copper, and brass. Answer: Why are LEDs more useful for testing the flow of electric current ? This happens because the when current is passed, the K+ ions are attracted to the metal sheet. Electroplating is a process that uses electric current to reduce dissolved metal ions by the use of … It is … Does pure water conduct electricity ? Question 4. LEDs require very little energy and glow even if a small current is passing through the circuit. Instead the iron can be galvanised or painted. Electrolysis is a method that uses a DC to drive a non-spontaneous chemical reaction. You would conclude that Solution: Some Uses of Electroplating: Imitation jewelry is made by applying a layer of gold or silver. What are conductors ? A cyanide-copper solution, for example, gave adherent deposits of copper directly on iron and steel. The disposal of waste products produced during the proces of electroplating is a major problem. Name three liquids, which when tested in the manner shown in figure, may cause the magnetic needle to deflect. • Question 4. Method : Question 2. (d) electro refining Your IP: 103.227.176.25 English Science. Answer: We have seen many times wherein artificial jewellery is shining when it is new and after sometime it begins to lose its shine. Add a teaspoonful of salt or a few drops of lemon juice to water to make it more conducting. If the ends of the wire of tester are touched for a long time, the cells will be finished very soon. Or, the bulb is fused? Now dissolve a pinch of common salt in distilled water. How can the magnetic effect be used as a tester ? Answer: As an extension, students can experiment with electroplating the different metal electrodes provided in the software, while predicting the results of different anode/cathode/solution combinations. The coating shall be produced from an aqueous electroplating system that may be either an alkaline or acid formulation. Electrolytes conduct current at a slow rate than metals. Hydroxyl ions (OH )move towards the anode and oxygen is collected on it. Distilled water is a Decoration of articles by giving them a layer for e.g., silver plating on cutlery. The process uses an … Iron is a strong metal used for making bridges. Compass needle shows deflection due to magnetic effect of electric current. We use the salt of the cathode as the electrolyte. Materials which do not allow electric current to flow through them are called insulators. Question 18. Apparently "MF" means a ferrous substrate in lots of different Japanese specs; "Zn-Ni" means zinc-nickel plating, "8" probably means 8 micron plating thickness. Answer: Zinc plating is identical to electro-galvanizing in principle because both are electro-deposition processes. Which electrode should be attached to the positive terminal of the battery and why? NCERT Solutions for Class 6, 7, 8, 9, 10, 11 and 12. Question 5. The ClassOne Solstice S8 is an 8-chamber system for high-performance, fully-automated electroplating and surface preparation. Watch Now. LED glows showing the flow of current. The loss of copper from solution is cqmpensated and the process goes on. Or, your cells are used up? Take out the ends of the tester from the lemon juice, dip them in water and then wipe them dry. But when salt is dissolved in pure water, it conducts electricity. Conductors : lemon juice, tap water. The free copper gets drawn to the plate connected to the negative terminal of the battery and gets deposited on that plate. But when salt is dissolved in distilled water and again tested, the bulb glows which shows that water containing salts conduct electricity. Question 5. Why we cannot make the whole article with chromium ? Gradually, a layer of copper builds up on the plate. Question 1. If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. Give some applications of electroplating. What is the disadvantage of electroplating done in the factories ? Recall the definition of a chemical change that you learnt in Class VII. A tester is used to check the conduction of electricity through two liquids, labelled A and B. For any content/service related issues please contact on this number . Answer: You are very important to us. Question 5. Objects that are electroplated are door handles, taps, rims of cycles, showers, the handlebar of cycles and bikes, gas burner, tin cans, metallic almirahs, buckles of belts, etc. as a point source of light in laser beam torches. Janhavi Govinda rao. [NCERT] Tin cans are made by electroplating tin on iron. Artificial jewellery is plated with silver or gold. Electroplating is the process of covering an object with a thin layer of metal by electrochemical deposition. It is found that the bulb of the tester glows brightly for liquid A while it glows very dimly for liquid B. Question 12. Electrodes are the metal rods which are dipped in liquids, to which cells are attached are called electrodes. Answer: This process is known as electroplating. 3. Topics covered are Good or Bad Conductors, tester and its Working, LED, complete and incomplete circuit and effects of current in effecting solutions. (d) sides of the container Name one non-metal which a good conductor of electricity. Therefore, there are many similarities between them. Hydrogen and Oxygen. Electroplating … Vinegar, lemon juice and tap water. Answer: (d) Potassium Why is chromium used for electroplating ? (c) electrolysis Do you find any difference in any one of them? (c), Question 7. Electroplating, process of coating with metal by means of an electric current. Explain how it can be used for writing. Can you think of the possible reasons? Answer: Materials which allow electric current to flow through them are called conductors. Test which solutions conduct electricity and which do not. Hello Cintadi. Can you explain the reason ? Allow the current to pass for about 15 minutes. No, pure water doesn’t conduct electricity. Answer: Question 8. Electrode is a medium of conduction of electricity. Prepare a list of objects around you that are electroplated. Applying a layer of chromium on an article by this method is called chrome plating. The deflection in magnetic needle shows that the circuit is complete and the solution conducts electricity, i.e., it is a good conductor. Answer: (b) The passage of an electric current through a solution causes _______ effects. Fill in the blanks. Parts of bicycle, motorbike and sanitary fittings are chrome plated by this method. Answer: Pour one teaspoon of lemon juice or vinegar in one cap. In case of a fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Electroplating: Electroplating is used for decorative purposes or to prevent a metal from corrosion. Electrolysis is the breaking up of a compound from its solution on passing electric current through the electrolyte. Do you find a coating over it? Question 3. Collect a few small plastic or rubber caps of discarded bottles and clean them. Call today! Learn the concepts of Class 8 Physics Chemical Effects of Electric Current with Videos and Stories. (a) conductor BNAT; Classes. Offered in aluminum, zinc, and tin plating processes. Answer: The coating finds application in screws and other light fasteners, light switch plates and other small parts. Let's know all about it in this session. Answer: In case of a fire, before the firemen uses the water hoses, they shut off the main electrical supply for the area. Answer: Paheli had heard that rainwater is as good as distilled water. Why should you not do the experiments on electricity by using electric supply from mains ? The … In what proportion the two products from electrolysis of water are obtained ? Is it safe for the electrician to carry out electrical repairs outdoors during heavy downpour? Electroplating is mainly done for avoiding corrosion of metals and for decorative purposes.Electroplating is a widely used process in many industries like automobiles, airplanes, electronics, jewelry, toys and many more. [NCERT]. Gradually, a layer of copper builds up on the plate. How will you carry out electroplating of copper in the laboratory. Class 1 - 3; Class 4 - 5; Class 6 - 10; Class 11 - 12; CBSE. Question 1. II. Observe the electrodes carefully. Question 8. Good conductors are those conductors that allow current to pass through them. When the free ends of a tester are dipped into a solution, the magnetic needle shows deflection. (b) insulator Answer: The thick rod of impure copper plate is to be attached to the positive terminal of the battery because when electric current is passed through the copper sulphate solution, it gets dissociated into copper and sulphate. It cannot be said for sure that liquid does not conduct electricity because : Question 2. Cloudflare Ray ID: 60770e65191819ac Answer: Offered in aluminum, zinc, and tin plating processes. The articles to be plated should be cleaned throughly to remove dust, grease or any deposit on it. It gets deposited on the (a) Most liquids that conduct electricity are solutions of ______ , ______ and ______ Answer: Answer: Class 8 Video | EduRev is made by best teachers of Class 8. Give some applications of electroplating. Answer: In this method, parts are placed on a wire rack, allowing each part to come into physical contact with the electrical power source. Articles Modern plating. Answer: Answer: (a) a good conductor. To her surprise she found that the compass needle showed deflection. Again test. (a), Question 4. (b) Oxalic acid If the ends of the wire of tester are touched for a long time, what will happen ? Which of the following metal is not extracted by electrolysis? Cyanide baths are the most operationally efficient but can potentially create pollutionand are hazardous. Question 2. CIP specializes in the unique process of mechanical plating and galvanizing that provides excellent corrosion resistance. Answer: Explain why they do this. 1. List the possible reasons. Therefore, we can be electrocuted in case we touch appliances with wet hands. You may also get distilled water from a medical store or a doctor or a nurse). Class 3: .0002" min plating thickness Salt spray test TYPE II 96 hours - check for white corrosion products. Question 2. Answer: What do you find? Answer: Copper from impure rod is sought to be transferred to the thin copper plate. Watch Now. Check that all the connections are tight. NCERT Books. needle the moment you dip the free ends of the tester in lemon juice? Does the bulb of the tester glow? How should LED be connected ? Protection of the surface of bases metals which corrode for e.g., iron is plated with chromium. Question 5. (i) The wires in the circuit may be loosely connected. A metal is released in the electrolysis of a salt. Question 9. We will need copper sulphate and two copper plates of size around 10 cm x 4 cm. Electroplating: It is the most common application of the chemical effect of electric current is electroplating. Answer: [NCERT] (a) conduction However, if the bulb does not glow, it means that the tester is not working. Deposits can be seen in containers uses for storing water. Which one of the following is a weak electrolyte ? The free copper, being positively charged, gets drawn to the negative terminal of the battery and gets deposited on it. Explain your answer. What is LED? Write on the paper with the end of the wire connected to the positive terminal. Question 11. We prefer not to do electroplating on iron used for bridges because it is very costly. On the other hand the loss of copper from the solution is regained from the impure copper rod which is attached to the positive terminal of the battery. Answer: Question 12. Thus water which is free of salts are poor conductors while water with salts is a good conductor of electricity. ZYCI PLATING SPECIFICATIONS - GENERAL INFORMATION Page 8 Reference Only April 2018 CHEMICAL FILM / CHROMATE MIL-C-5541 Coatings for aluminum, zinc, silver, and cadmium. Answer: Materials which allow electric current to flow through them are called conductors. Write short note on. Dinesh can study the chemical effect of current at home very easily. Question 2. EXAMPLE SPECIFICIATION: DONT USE CADMIUM ANY MORE, PLEASE. Now immerse the electrodes in this solution. Is air an insulator or conductor of electricity ? Answer: Wait for 3-4 minutes. Answer: Answer: Bring your tester over this cap and let the ends of the tester dip into lemon juice or vinegar as shown in Fig. Explain why they do this. Take the tray from inside a discarded matchbox. Does distilled water conduct electricity? 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