Description : During electrolysis of aqeous solution of NaCl, there are two type of anions are present Cl- and –OH, Cl- is discharged first than –OH,although it is present below Cl- in electrochemical series. Give reason.
Last Answer : Ans: During this electrolysis process Chloride ions come from NaCl, which is a strong electrolyte and ionize to large extent so concentration of chloride ions in solution will be high. ... chloride ions it is first discharged despite of its presence above than hydroxyl in electrochemical series.
Description : Why carbon electrode is used during electrolysis of Nacl, instead of Pt electrode?
Last Answer : Ans: During electrolysis of Nacl, chlorine gas is produced at anode. Thus to avoid it’s reaction with platinum we use carbon electrode.
Description : Why sulphuric acid is added to the water during electrolysis of water?
Last Answer : Ans: It is added to increase conduction of the water, because water is a weak electrolyte.
Description : Chlorine gas is produced by the electrolysis of brine (NaCl solution with solid NaCl make up) in mercury electrolytic cell. Which of the following is the anodic reaction? (A) Oxidation of Na + ions (B) Oxidation of Cl - ions (C) Reduction of Na + ions (D) Reduction of Cl - ions
Last Answer : (B) Oxidation of Cl - ions
Description : In Down’s cell, why the reaction between sodium metal and chlorine gas must be avoided? And how could we prevent reaction between them?
Last Answer : Ans:In Down’s cell electrolysis of fused NaCl yields sodium metal and chlorine gas .If these are not separated these will react to form Nacl again. So to prevent these reaction in Down’s cell, we place a steel gauze between cathode and anode.
Description : Ions moving towards the cathode during electrolysis of an aqueous solution of Ca(OH)2 are (a) OH (b) H+ (c) Ca2+ (d) 02
Last Answer : Ans:(a)
Description : Why gold ,silver and pt are used in making ornaments?
Last Answer : Ans: Because these are nobel metals and therefore their rusting doesn,t occure and also these are very lustorous(shiny),so due to these qualities ,these are used for making ornaments.
Description : Why for chromium plating iron is firstly platted by copper or nickel?
Last Answer : Ans: Because chromium metal doesn’t adhere directly to the iron properly so it is firstly plated with nickel or copper.
Description : What is electroplating and what is its objective?
Last Answer : Ans:The process in which one metal is deposited at other electrolytically. It is very useful process and following are objective of electroplating. (a) Deposition of Nobel metals on inferior metals. (b) Protection of different metals from corrosion. (c) Repair of broken machinery.
Description : Why cation present below in electrochemical series can discharge before the elements present above them in an electrochemical cell?
Last Answer : Ans: This is because their ability to be reduced (reduction potential) is more than the cation present above them in electrochemical series. So they take electrons before the other cations and get discharged.
Description : What is modern theory about the existence of the ionic compounds in solid state?
Last Answer : Ans: According to modern theory these exist in form of ions even in solid state for example, sodium chloride exist as Na+ Cl- . Whereas according to the ionic theory it exists as NaCl.
Description : Why an electrolyte in molten or fused state is electrically neutral?
Last Answer : Ans: Because the number of + ve charges and –ve charges are equal , so as a result an electrolyte appears to be neutral in nature.
Description : Why ionic compounds are non conductor in solid state and conductor in molten or fused state?
Last Answer : Ans: This is because in solid state there are no free ions and their free movement isn’t possible but in molten or fused state the free movement of ions is possible, so these can conduct electric current.
Description : What is “redox” reaction?
Last Answer : Ans: “The reaction in which both reduction and oxidation takes place is called redox reaction. Reduction: “Addition of electron in an atom”. Oxidation: “Removal of electron from an atom”.
Description : What is difference between electrolytic and voltaic cell?
Last Answer : Ans:In electrolytic cell a non-spontaneous redox reaction is carried out with help of electrical energy. Wherease In voltaic cell a spontaneous redox reaction generates the electrical energy.
Description : Ionic non polar solid dielectrics contain more than one type of atoms but no permanent dipoles. State True/False a) True b) False
Last Answer : a) True
Description : In a magnetic material, always there exist magnetic dipoles as well as monopoles. State True/False. a) True b) False
Last Answer : b) False
Description : In a static magnetic field only magnetic dipoles exist. State True/False. a) True b) False
Description : Which among the following is false about acids? (1) They give H+ ions in aqueous solution (2) Most acids contain hydrogen (3) They turn blue litmus red (4) They are bad conductor of electricity in aqueous solution
Last Answer : (4) They are bad conductor of electricity in aqueous solution Explanation: Acids are good conductors of electric current in aqueous solution. When acids come in contact with water, they liberate OH ions, resulting in conduction of electricity.
Description : During the electrolysis of a dilute aqueous solution of sulfuric acid, what happens to the sulfuric acid concentration?
Last Answer : ANSWER: IT REMAINS THE SAME
Description : Electrolysis is an impotant technique for extraction of metals, and each of the solution needs a minimum voltage to get discharged and this value is e
Last Answer : Electrolysis is an impotant technique for extraction of metals, and each of the solution needs a minimum voltage to get ... 3)` D. `H_(2)S_(2)O_(8)`
Last Answer : Electrolysis is an impotant technique for extraction of metals, and each of the solution needs a minimum voltage to get ... ,H_(2)` D. `O_(2),H_(2)`
Last Answer : Electrolysis is an impotant technique for extraction of metals, and each of the solution needs a minimum voltage to get ... ` C. `Br_(2)` D. `O_(2)`
Description : Electrolysis of an aqueous solution of copper sulphate using copper electrodes gives (1) Copper at eathode and oxygen at anode. (2) Copper at anode and oxygen at cathode. (3) Copper at cathode and anodes dissolve to give copper. (4) Hydrogen at cathode and oxygen at anode.
Last Answer : (1) Copper at eathode and oxygen at anode. Explanation: Copper is deposited at the cathode and is dissolved at the anode. Consequently the concentration of copper ions in solution remains constant. This can be used as a method of purification of copper as only pure copper is deposited at the cathode
Description : Why are substances like Platinum and Palladium offer used for carrying out electrolysis in aqueous solution ?
Last Answer : Platinum and palladium is inert electrodes. They are not react with the ions of electrolyte and products of electrolysis. Hence they are used as electrodes during electrolysis. Hence they ... electrodes during electrolysis. Hence they are used as electrodes during electrolysis in aqueous solution.
Description : Electrolysis of an aqueous solution of copper sulphate using copper electrodes gives (1) Copper at cathode and oxygen at anode. (2) Copper at anode and oxygen at cathode. (3) Copper at cathode and anodes dissolve to give copper. (4) Hydrogen at cathode and oxygen at anode.
Last Answer : Copper at cathode and oxygen at anode.
Description : Which of the following pairs of compounds could NOT be used to create a buffer solution? Would it be: w) HCL and NaCl (read: H - C - L and N - A - C - L) x) HCN and NaCN (read: H - C - N and N - A - C - N) y) NH3 ... - H - 4 - C - L) z) HNO2 and NaNO2 (read: H - N - O -2 and N - A - N - O - 2)
Last Answer : ANSWER: W -- HCL AND NaCl (read: H - C - L and N - A - C - L)
Description : What products do we get on electrolysis of saturated brine using steel cathode and graphite anode in an electrolytic cell? (A) Cl2 & Na (B) Cl2 & H2 (C) O2 & H2 (D) Cl2 , H2 & NaOH solution
Last Answer : (D) Cl2 , H2 & NaOH solution
Description : During electrolysis, which the species are discharged at cathode? -Do You Know?
Last Answer : answer:
Description : During electrolysis, the cations and anions of the electrolyte are 1. Discharged 2. Hydrolysed 3. In motion 4. Hydrated The correct answers are: (a) 1 and 3 (b) 2 and 4 (c) 3 and 4 (d) 1 and 2
Description : During electrolysis, which the species are discharged at cathode?
Last Answer : Cations
Description : Electrolysis of aqueous solution of Brine (NaCI) gives
Last Answer : Electrolysis of aqueous solution of Brine (NaCI) gives A. (A)`Cl_2` B. (B) `H_2` C. (C) NaHO D. (D) all of these
Description : The metal which cannot be obtained by electrolysis of aqueous solution of its salts is
Last Answer : The metal which cannot be obtained by electrolysis of aqueous solution of its salts is A. Ag B. Mg C. Cu D. Al
Description : An aqueous solution of CuSO4 is acidic in nature because the salt undergoes (a) dialysis (b) hydrolysis (c) electrolysis (d) photolysis
Last Answer : Ans:(b)
Description : An aqueous solution of glycine is neutral because of the formation of : (a) Carbanion (b) Zwitterion (c) Carbonium ions (d) Free radicals
Last Answer : Zwitterion
Description : `Na_(2)CO_(3),NaCl, NaNO_(2),Na_(2)SO_(3),NaBr,CH_(3)CO O Na` are separately treated with `AgNO_(3)` solution. In how many cases white precipitate is/
Last Answer : `Na_(2)CO_(3),NaCl, NaNO_(2),Na_(2)SO_(3),NaBr,CH_(3)CO O Na` are separately ... solution. In how many cases white precipitate is/are obtained.
Description : Saline solution is given to patients of cholera because (a) Na+ prevents water loss from body (b) NaCl function as regulatory material (c) NaCl produces energy (d) NaCl is antibacterial.
Last Answer : (a) Na+ prevents water loss from body
Description : Pick out the wrong statement. (A) At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature (B) Normally, the gases which are easily liquefied are more soluble ... (D) At constant pressure, solubility of a gas in a liquid increases with rise in temperature
Last Answer : (A) At constant pressure, solubility of a gas in a liquid diminishes with rise in temperature
Description : An aqueous solution of sodium chloride is prepared by dissolving 10kg of sodium chloride in 50 kg of water find (i) Weight % (ii) Mole % of solution. [Atomic weight of Na = 23, Cl = 35.5]
Last Answer : Weight of NaCl = 10 kg Weight of H2O = 50 kg Total weight = 60 kg Weight % of NaCl = (10/ 60) * 100 =16.67% Weight % of H2O = (50/ 60) * 100 = 83.33% Molecular weight of NaCl = 58.5 k moles of NaCl ... 100 = 5.79% Mol % of H2O = (moles of H2O / Total moles)*100 = (2.78/ 2.949)*100 = 94.26%
Description : `XeO_(3)` forms xenate ion in alkaline medium. `XeO_(3) +NaOH rarr Na[HXeO_(4)]` But the xenate ions slowly disproportionate in alkaline solution as `
Last Answer : `XeO_(3)` forms xenate ion in alkaline medium. `XeO_(3) +NaOH rarr Na[HXeO_(4)]` But the xenate ions slowly ... `Na_(4)XeO_(6)` D. `Na_(4)XeO_(4)`
Description : The theory of interionic attraction attributed to Debye and Hückel: w) was disproved by Arrhenius x) accounts quantitatively for the attraction between ions in dilute aqueous solutions y) does not account for kindered "ion-activity" z) accounts for intra-molecular polar bonds
Last Answer : ANSWER: X -- ACCOUNTS QUANTITATIVELY FOR THE ATTRACTION BETWEEN IONS IN DILUTE AQUEOUS SOLUTIONS
Description : 1.0 molal aqueous solution of an electrolyte `"A"_(2)"B"_(3)` is 60% ionised. The boiling point of the solution at 1 atm is `("K"_("b"("H"_(2)"O"))=0.
Last Answer : 1.0 molal aqueous solution of an electrolyte `"A"_(2)"B"_(3)` is 60% ionised. The boiling point of the solution at ... C. `376. 4 K` D. ` 374 . 76 K`
Description : In the electrolysis of silver chloride, a charge of `4xx10^(5)` C is flowing through the electrolyte. Calculate the number of silver `(Ag^(+))` ions f
Last Answer : In the electrolysis of silver chloride, a charge of `4xx10^(5)` C is flowing through the electrolyte. ... silver `(Ag^(+))` ions flowing through it.
Description : Which of the metallic ions is essential for blood clotting? (1) Na+ (2) Ca++ (3) K+ (4) Fe++
Last Answer : (2) Ca++ Explanation: Clotting also requires: calcium ions (Ca2+)(which is why blood banks use a chelating agent to bind the calcium in donated blood so the blood will not clot in the bag). about a dozen other protein clotting factors.
Description : During the propagation of a nerve impulse, the action potential results from the movement of (a) K+ ions from intracellular fluid to extracellular fluid (b) Na+ ions from extracellular ... extracellular fluid to intracellular fluid (d) Na+ ions from intracellular fluid to extracellular fluid.
Last Answer : (b) Na+ ions from extracellular fluid to intracellular fluid
Description : The concentration of (H+) ions is 4 x 10-5in a solution. Then pH of the solution will be (Given log 4 = 0.6) (A) 4.4 (B) 5.6 (C) 8.4 (D) 2.4
Last Answer : (A) 4.4
Description : In a neutral solution (A) H+ions are absent (B) OH ions are absent (C) Both H+ and OH ions are present in very small but equal concentration (D) None of these
Last Answer : (C) Both H+ and OH ions are present in very small but equal concentration
Description : The specific gravity of the electrolyte solution in a lead acid battery _____________. A. is not effected during charging B. remains the same during discharge C. would read close to 1.830 when discharged D. gives an indication of the state of charge of the battery
Last Answer : Answer: D
Description : State as to why: (a) A solution of Na2CO3 is alkaline? (b)alkali metals are prepared by electrolysis of their fused chlorides ? (c)sodium is found to be more useful than potassium ?
Last Answer : Ans. (a) It undergoes hydrolysis to produce a strong base NaOH . (b) When the aq. Solution of any alkali metal is subjected to electrolysis ,H2 instead of the alkali metal is produced at the ... of sugars and amino acids into the cells. Thus, sodium is found to be more useful than potassium.