NCERT Solutions for Class 6, 7, 8, 9, 10, 11 and 12. Solution: Question 11. Answer: Explain. of distilled water in a clean and dry beaker. (c) If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the ________ terminal of the battery. Question 9. Write its one use. Nov 8, 2020 • 1h 5m . The salts separate out and deposit on the sides of the container. Gold does not corrode. Question 10. Class 8: Science: Chemical Effects of Electric Current: electroplating Add a few drops of dilute sulphuric acid to copper sulphate solution to make it more conducting. If not, what can we do to make it conducting? A materials scientist extolls the virtues of electroplating. The rainwater showed deflection with the tester because it is not as pure as distilled water. No, it is not advisable for electrician to carry out electrical repairs during heavy downpour because water is a good conductor of electricity and the person can get shock. Question 15. A cell consists of two electrodes (conductors), usually made of metal, which are held apart from one another. Class 3: .0002" min plating thickness Salt spray test TYPE II 96 hours - check for white corrosion products. Question 6. (c) electrolysis What is the objective of electroplating ? Video on Electroplating Class 8 Science Chapter 14 Chemical Effects Of Electric Current for CBSE Board explaining the process of electroplating with activity. 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. [NCT 2011] (i) liquid A is a better conductor than liquid B. What are electrodes? Answer: First and second cap with acid and base respectively, conducts electricity whereas third cap having sugar dissolved in distilled water do not conduct electricity. A metal is released in the electrolysis of a salt. What colour is the coating? Question 4. Electroplating can be described as an application of electrolysis since electrolysis is the basic technique used for electroplating. Conductors : lemon juice, tap water. [NCERT] Electroplating. Answer: From the other plate, an equal amount of copper gets dissolved in the solution. It has the sound of a JIS spec for zinc plating … We call these two rods electrodes. LED glows showing the flow of current. What do you find? (d) chemical energy into magnetic energy (d) sides of the container Class 1 - 3; Class 4 - 5; Class 6 - 10; Class 11 - 12; CBSE. Cyanide baths are the most operationally efficient but can potentially create pollutionand are hazardous. 3. Activity 2 (NCERT Textbook, Page 773) Let's know all about it in this session. Air is an insulator of electricity. Hydroxyl ions (OH )move towards the anode and oxygen is collected on it. Answer: Materials which do not allow electric current to flow through them are called insulators. Answer: Electroplating … (a) Aluminium Electroplating Mention the components of the circuit of tester How will you identify the positive terminal of a battery if it is hidden in a box and you can only see two of its leads. The current is provided by an external power supply. DK, 2007/2016. It is also called the substrate. It is found that the bulb of the tester glows brightly for liquid A while it glows very dimly for liquid B. What is electrolysis ? We cannot make the whole article from it because it is a very costly metal. (c) semi-conductor (b), Question 8. Good conductors are those conductors that allow current to pass through them. Solution: Which out of the following does not conduct electricity ? The free copper gets deposited on the plate acting as cathode. 2-this process uses harmful chemicals that can result in death. Answer: Answer: Electroplating Mention the components of the circuit of tester How will you identify the positive … Add a little sugar to the distilled water in the third cap and dissolve it. It can cause electrocution, as water is a good conductor of electricity. When electric current is passed through copper sulphate solution, the copper sulphate breaks up into copper and sulphate ions. In liquids, the movement of charged particles (ions) carry current from anode to cathode terminals. Electroplating is widely used in indus Give some uses of LED. Stainless steel revolutionised eating after centuries of a bad taste in the mouth by Mark Miodownik. Instead the iron can be galvanised or painted. What could be the reasons? Question 6. Take out carbon rods carefully from two discarded cells. Parts of bicycle, motorbike and sanitary fittings are chrome plated by this method. Electroplating is the deposition of metal, from an electrolyte onto an electrode. If you are at an office or shared network, you can ask the network administrator to run a scan across the network looking for misconfigured or infected devices. Similar Classes. Why should you not do the experiments on electricity by using electric supply from mains ? So she collected some rainwater in a clean glass tumbler aifd tested it using a tester. But when salt is dissolved in distilled water and again tested, the bulb glows which shows that water containing salts conduct electricity. Answer: Question 9. Liquid A is a better conductor of electricity because the bulb glows more in it. [clarification needed To her surprise, she found that the compass needle showed deflection. CIP specializes in the unique process of mechanical plating and galvanizing that provides excellent corrosion resistance. Question 7. What is the disadvantage of electroplating done in the factories ? Place a small compass needle inside it. So, the fire¬men shut off the electric supply before spraying water to save themselves and other people from electrocution. Zigya App. Allow the current to pass for about 15 minutes. Materials which allow electric current to flow through them are called conductors. The possible reasons for this are : Question 4. This completes the circuit of the tester and the bulb should glow. What are conductors ? He finds that the compass needle deflects more in the case of seawater. In electroplating, a complete layer of a second metal is deposited on a first metal by electrolysis. Write short note on. Question 5. Top Now rinse them with water and dry them. A cyanide-copper solution is still used for this purpose and also for the initial plating on zinc die castings. Question 13. Gradually, a layer of copper builds up on the plate. 343 Views. Do you find a coating over it? Answer: CBSE Class 10; CBSE Class 12; JEE Main Papers; JEE Advanced Papers; NEET Papers; KCET Papers; Mock Tests. The process uses an … Attach the free ends of the wires to a LED. (b), Question 6. The seawater contains a huge amount of salts in comparison to drinking water, hence the seawater is a better conductor of electricity and it produces a stronger magnetic field in the wire and hence deflects the compass needle more. Question 18. (c) cathode What are … acids, bases, salts. The writing appears on the paper. A tester can be made by attaching one free end of the wire to a terminal of a battery and another wire from other terminal of the battery to a bulb. Is it safe for the electrician to carry out electrical repairs outdoors during heavy downpour? Note down the terminal of the battery with which this electrode is connected. The disposal of waste products produced during the proces of electroplating is a major problem. The electrode, connected to the positive terminal of a battery, is called Answer: Why the iron cans are electroplated with tin ? Answer: Paheli had heard that rainwater is as good as distilled water. Answer: Classify the following liquids into conductors and insulators : lemon juice, , distilled water, tap water, milk. Question 1. Question 6. Question 13. The two free ends of wire are connected to the material to be tested. The process of depositing a layer of any desired metal on another material by means of electricity is called …………. Wrap an electric wire a few times around the tray. Question 8. Janhavi Govinda rao. The entire NCERT … Question 8. Name three liquids, which when tested in the manner shown in figure, may cause the magnetic needle to deflect. Most liquids that conduct electricity are solutions of …………, ………. Hindi Mathematics. • If the tester is working, it can be used to test the materials, i.e., whether it is a conductor or non-conductor of electricity. Why ? Solution: CIP specializes in the unique process of mechanical plating and galvanizing that provides excellent corrosion resistance. (b) electrical energy into chemical energy Answer: Take another piece of wire and connect it to the other terminal of the battery (Fig. Take two pieces of copper wire and iron wire. 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. Fasteners of High tensile class 12.9 are generally supplied unplated with an oil quenched finish, where the vast majority of lower tensile fasteners are coated; this includes Metric class 8.8, USA grade 5 and lower grade/class. 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. However, Class 2A thread allowances in sizes No. What is electroplating? Question 1. [NCERT] Check that all the connections are tight. Method : Question 2. When electric current is passed in water hydrogen ions (H+) move towards cathode and get collected over it. Now remove the electrodes from the solution and look at them carefully. Electroplating … You would conclude that. Rack electroplating: Rack or wiring plating is a good option if you need to plate large groups of parts. Answer: Class 8 Video | EduRev is made by best teachers of Class 8. Free PDF Download - Best collection of CBSE topper Notes, Important Questions, Sample papers and NCERT Solutions for CBSE Class 8 Science Chemical Effects of Electrical Current. Answer: 14.2). How can he do it ? Gold plating is a method of depositing a thin layer of gold onto the surface of another metal, most often copper or silver (to make silver-gilt), by chemical or electrochemical plating.This article covers plating methods used in the modern electronics industry; for more traditional methods, often used for much larger objects, see gilding. Solution: The electrodepositing reaction takes place in an electrolytic solution… (d) electroplating. (d) semi-insulator What are insulators ? So she collected some rainwater in a clean glass tumbler and tested it using a tester. Electric charge on ions is used for writing with an electric pen. (b), Question 3. In this activity, if the bulb does not glow, it means that either the connections of the circuit are loose or the bulb is fused or cells are used up. Take out the ends of the tester from the lemon juice, dip them in water and then wipe them dry. 206k watch mins. Answer: (c) half on the anode and half on the cathode Now test if the tester is working or not. The bulb does not glow in the setup shown in Fig. Answer: Use the tester to test whether distilled water conducts electricity or not. Please enable Cookies and reload the page. (b) The passage of an electric current through a solution causes _______ effects. Question 1. The zinc is applied as an expendable electrode in a cyanide, alkaline non-cyanide, or acid chloride salt solution. Answer: (b) Oxalic acid Gradually, a layer of copper builds up on the plate. Question 8. Compact Fluorescent Lamps. Name the gases formed when electric current is passed in water containing a few drops of acid ? Answer: [NCERT]. Share. In electroplating the word electro stands for electric current and plating means the act of covering a metal object with a thin layer of coating of a different metal Electroplating The process of depositing a thin layer of a desired metal over a metal object with the help of electric current is called electroplating . Conclusion. You may also get distilled water from a medical store or a doctor or a nurse). Therefore, it becomes thin. Zinc plating is identical to electro-galvanizing in principle because both are electro-deposition processes. Chemical effects of electric current are used widely and one of the effect is electroplating. NCERT Solutions. Though more expensive, this option is optimal for more delicate parts that cannot undergo barrel plating. needle the moment you dip the free ends of the tester in lemon juice? If the tester is put in distilled water, the bulb of the tester does not glow. 1. It is … How will you carry out electroplating of copper in the laboratory. Electrode is a medium of conduction of electricity. The coating shall be adherent, free from blisters, pits, or discontinuities, and shall be free of cracks in the as plated state. Explain why these deposits occur. Does the bulb of the tester glow? Answer: The disposal of the used conducting solution after electroplating is hazardous and can cause environmental pollution. Ended on Nov 15, 2020. as a point source of light in laser beam torches. Tin is less reactive than iron. Your tester with two free ends of the wire is ready. Answer: Materials which allow electric current to flow through them are called conductors. BOOK FREE CLASS; COMPETITIVE EXAMS. Distilled water does not have any salts dissolved in it, but rain water may have some impurities in it. Watch Now. Can you explain the reason ? Cloudflare Ray ID: 60770e65191819ac (a) conduction Now connect one free end of the wire to the terminal of a battery. What can be the possible reasons for this ? ZYCI PLATING SPECIFICATIONS - GENERAL INFORMATION Page 8 Reference Only April 2018 CHEMICAL FILM / CHROMATE MIL-C-5541 Coatings for aluminum, zinc, silver, and cadmium. Electroplating is conducted in an electrolytic cell. Depending on the coatings, or combinations of coatings, selected a variety of outcomes can be gained. Chromium is used for electroplating because it has a shiny appearance, does not corrode and is scratch resistant. Your IP: 103.227.176.25 In case of a fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Question 9. 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