Answer: (i) Nickel sulphate (ii) Key chain (iii) Pure nickel plate (iv) Ni2+ + 2e–  ⟶   Ni (v) Ni – 2e–   ⟶   Ni2+. Question 4: Study the given figure and answer the question that follow : (i) Why silica crucible is used in this type of electrolysis ? Studyrankers is a free educational platform for cbse k-12 students. Name the sodium compound which is used for softening hard water. They are KNO3, AgNO3, Zn(NO3)2, Ca(NO3)2. 12.A milkman adds a very small amount of baking soda to fresh milk. (i) dry HCl gas does not change the colour of the dry blue litmus paper. APlusTopper.com provides ICSE Solutions for Class 10 Chemistry Chapter 6 Electrolysis for ICSE Board Examinations. Acids transform red … (iii) Write two applications of electrolysis in which the anode diminishes in mass. Answer: Sea water is a strong electrolyte because sodium chloride dissolved in it dissociates completely into free mobile ions. The definitions of Acids and Bases in terms of furnishing of H. At lower pH below 5.5, the calcium phosphate of enamel of tooth is corroded. Acidified copper sulphate solution with platinum electrode. As the electrolysis is . Question 12: During electrolysis high voltage is not favoured. Reaction of cathode: H+ + e–   ⟶   H H + H   ⟶   H2 Reaction of anode : OH– – 1e–  ⟶   OH 4OH   ⟶    2H2O + O2(g). Answer: It is done because water is a non-electrolyte, so it can be electrolytically decomposed by removing the H+ and OH– ions continuously because the negligible ionization of water yields H+ and OH– ions which recombine to form a water molecule, then another molecule will ionize. Answer: The sulphuric acid just helps in increasing the conductivity of water. Therefore due to absence of free ions, wax does not conduct electricity. This is called levling effect. When it is dissolved in water, does not dissociate to give free ions which could migrate to cathode or anode. Cu++ ions are discharged at the cathode and deposited as Pinkish copper metal, but OH– ions are discharged at anode. Thus concentration of copper ions goes on decreasing. You have been provided with three test tubes. Hence, mercury is a metallic conductor and not an electrolyte. (iii) Copper ions (Cu2+) are likely to discharge at cathode, because their position is lower than hydrogen ions H+ in electrochemical series. (Provide the missing words.) Download Formulae Handbook For ICSE Class 9 and 10. Answer: (i) (a) The ratio is 2 : 1 (b) H+ + e–   ⟶   H; 2H + 2H   ⟶   2H2 (ii) Addition of sulphuric acid causes dissociation of water molecules into [H+] and [OH–] ions. Add the water into the bowl with your weighed salt. Similarly.strong bases like NaOH. Question 25: Mr. Ramu wants to electroplate his key chain with nickel to prevent rusting. What is the common name of the compound CaOCl. Question 2: Metals like potassium, calcium, sodium, etc., can be extracted only by electrolysis. Question 21: Mention the type of ions present, the products obtained and the electrode reactions that occur, when the following are electrolysed : (i) Molten lead bromide between steel cathode and graphite anode. (iii) Write the reactions at the cathode and at the anode. For example, if sodium chloride (NaCl) is dissolved in water, it ionizes to form Na + and Cl-ions. 4. (c) dilute sulphuric acid reacts with aluminium powder. Thus concentration of copper ions in electrolyte remain unchanged. Thus, only electricity is suitable as reducing agent which provides unlimited amount of energy to break ionic bonds easily. Answer: When an iron rod is dipped in CuSO4 solution, iron displaces copper from CuSO4 to form FeSO4 which is light green in colour. (ii) If Y is a diatomic gas, write the equation for the direct combination of X and Y to form a compound. Question 13: While electrolysing concentrated sulphuric acid, the bulb glows very dimly but when diluted, the bulb glows brightly. The pH of rain water collected from two cities A and B was found to be 6 and 5 respectively. 4. How is the concentration of hydroxide ions (OH. (iii) Cone, of H 3 O + ion is affected when a solution of an acid is diluted. Five solutions A, B, C, D and E when tested with universal indicator showed pH as 4, 1, 11, 7 and 9, respectively. Question 5: An electrolytic all is an set up using two platinum electrodes and an aqueous solution of copper (II) sulphate. M + M   ⟶  M2 (v) Oxygen gas is liberated at anode. In the above context answer the following: (i) What kind of combination exists between M and O ? Hence they do not show acidic character. (iii) Lead bromide should be in molten state, if it is to conduct electricity. Which of this is acidic and which one is basic? (ii) How many electrons are there in the outermost shell of M ? 1 point is earned for a correct explanation. This oxide when dissolved in water forms the corresponding hydroxide which is a good conductor of electricity. Mercury has strong tendency to form an amalgam with : sodium Na+ + e–   ⟶   Na Na + Hg   ⟶  Na/Hg When the sodium amalgam dissolves in water, the reaction is 2Na/Hg + 2H20   ⟶  2NaOH + H2 + Hg. The compound will be soluble in water. Silver wire and a spoon, which is to be plated with silver, are dipped in the solution. c.) 12.9 g of carbon tetrachloride dissolved in 72.5 g of benzene Metal compound A reacts with dilute hydrochloric acid to produce effervescence. (ii) Colour of electrolyte gradually fades from blue to colourless. In electrode reactions, the positively charged ions (cations) accept electrons from cathode to form neutral atoms, i.e., at cathode reduction’takes place. (v) The ions will not be discharged at electrode during electrolysis are H+ and OH–. How will you test for the presence of this gas? Question 1: (i) Name the cathode and anode used during electroplating of silver. Name the substance which on treatment with chlorine yields bleaching powder? Hence, they are also called Redox reactions. The spoon is coated with silver and looks as a silver spoon. (iii) Write the equations of the reactions which take place at the cathode and anode when acidified water is electrolysed. (i) Write equations to show how X and Y form ions. Increase in resistance can only be obtained by applying low voltage during electrolysis. The presence of mobile ions makes the aqueous solution of ammonia able to conduct electricity. Question 1: Why are adds, bases and salts classified as electrolytes? Give two examples. Question 15: Why should water be acidified before proceeding with the electrolysis of water ? Question 10: A certain metal, say M, does not liberate hydrogen from dilute sulphuric acid, but displaces copper from aqueous copper (II) sulphate. Answer: (i) Cathode: Highly cleaned article such as copper cup. 1. (d) dilute hydrochloric acid reacts with iron filings. Hint: Remember that a solution consists of both solute and solvent. Triaxial Tests on Water-Saturated Gas Hydrate-Bearing Fine-Grained Samples of the South China Sea under Different Drainage Conditions. Answer: The blue colour of electrolyte is due to the presence of copper ions in it. 3. If you are given only red litmus paper, how will you identify the contents of each test tube? Hence, solution of sodium chloride is good conductor of electricity. Answer: (i) X – 2e–   ⟶   X2+ Y + 3e–   ⟶   Y3- (ii) 3X+2 + 2Y-3   ⟶   X3Y2 (iii) (1) Electroplating of Metals. // Zach Ferenbaugh Elk, Assistant Laboratory Animal Technician Salary, Wholesale Scorch Torch, How Much Is A Canadian Passport 2020, Used Rv Air Conditioner'' - Craigslist, Osha 30 Youtube,