Description : How could we prevent H+ ions to be discharged first than Na+ during electrolysis of aqueous solution of NaCl?
Last Answer : Ans: This could be prevented by using mercury cathode during this kind of electrolysis, because H+ ions need high voltage to be discharged at mercury cathode. In this way sodium got discharged at cathode despite H+ ions.
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 “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 : 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 : 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 : 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 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 : 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 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 : 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
Last Answer : a) True
Description : Ionic non polar solid dielectrics contain more than one type of atoms but no permanent dipoles. State True/False a) True b) False
Description : A couple, both severely retarded/down's syndrome/etcetera: should society literally prevent them from having children?
Last Answer : Your other question was easier. Neither of them are able to take care of the child?
Description : Which of the following reactions involve NEITHER oxidation nor reduction? w) burning antimony in chlorine x) decomposition of potassium chlorate y) reaction of sodium with water z) reaction of potassium hydroxide with nitric acid
Last Answer : ANSWER: Z -- REACTION OF POTASSIUM HYDROXIDE WITH NITRIC ACID
Description : Narrate how particular dam in a flood-prone area has recently failed to prevent a flood. Find out why it happened. Could this be avoided? How? -Geography
Last Answer : In the year 2006, the floods that occurred in Maharashtra and Gujarat were due to the aggravation of floods by the opening of gates of dams. The major cause of this was the sedimentation in the ... water tanks if made in every house, will help in storing water in the case of heavy rainfall.
Description : 45. When Cl2 gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from (1) Zero to + 1 and zero to –3 (2) Zero to +1 and zero to –5 (3) Zero to –1 and zero to + 5 (4) Zero –1 and zero to + 3
Last Answer : Zero to –1 and zero to + 5
Description : Iodised salts contains the iodine salts of which metal? A. Iodine B. Potassium (Answer) C. Sodium Chloride D. Chlorine
Last Answer : B. Potassium (Answer)
Description : Semibatch reactor is preferred, when a/an (A) A highly exothermic reaction is to be controlled (B) Undesirable side reaction (at high concentration of one of the reactants) is to be avoided (C) A gas is to be reacted with liquid (e.g. hydrogenation of fat) (D) All (A), (B), and (C
Last Answer : (D) All (A), (B), and (C
Description : Chlorine on reaction with hot and concentrated sodium hydroxide gives:
Last Answer : Chlorine on reaction with hot and concentrated sodium hydroxide gives: A. `ClO_3^-` and `ClO_2^-` B. `Cl^-` ... and `ClO_3^-` D. `Cl^-` and `ClO_2^-`
Description : Which of the following actions have to be avoided to prevent the depletion of DO (dissolved oxygen) in aquaculture? [a] Over-aerating, over-warming, over-harvesting [b] Over-seining, over-planting, over- ... c] Over-feeding, over-stocking, over-fertilizing [d] None of these [e] All of the above
Last Answer : [c] Over-feeding, over-stocking, over-fertilizing
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 : (a) Define a balanced chemical equation. Why should an equation be balanced? (b) Write the balanced chemical equation for the following reaction: (i) Phosphorus burns in presence of chlorine to form phosphorus penta chloride. (ii) Burning of natural gas. (iii) The process of respiration. -Chemistry
Last Answer : Answer. (a) Balanced chemical equation has an equal number of atoms of different elements in the reactants and products. According to law of conservation of mass, matter can neither be created nor be destroyed in a chemical ... C6H12O6 (s) + 6O2 (g) + 6H2O ---> 6CO2 (aq) + 12H2O (l) + energy
Description : The reactions of `CI_(2)` gas with cold-dilute and hot-concentrated NaOH in water give sodium salts of two different oxioacids of chlorine, P and Q, r
Last Answer : The reactions of `CI_(2)` gas with cold-dilute and hot-concentrated NaOH in water give sodium salts of ... `H_3PO_2` D. `SOCl_2 , PCl_5` and `H_3PO_5`
Last Answer : The reactions of `CI_(2)` gas with cold-dilute and hot-concentrated NaOH in water give ... porchloric acids D. (D) chloric and hypochlorus acids
Description : What is the balance of chlorine gas reacts with sodium and produce sodium chlorine?
Last Answer : The chemical reaction is:2 Na + Cl2 = 2 NaCl
Description : Is a physical change A.Forming a mixture B.Burning wood C.Food turning into waste in the intestines D.Turning solid sodium and chlorine gas into salt?
Last Answer : What is the answer ?
Description : A compound X' on heating with excess conc. sulphuric acid at 443 K gives an unsaturated compound Y'. X' also reacts with sodium metal to evolve a colourless gas Z'. Identify X', Y' ... the chemical reaction of formation of Y' and also write the role of sulphuric acid in the reaction. -Science
Last Answer : X-Ethanol/ (C2H5OH)/Ethyl AlcoholY- Ethene / (C2H4)Z- Hydrogen/ (H2)Role of sulphuric acid - dehydrating agent
Description : (a) Explain two ways by which food industries prevent rancidity. (b) Discuss the importance of decomposition reaction in metal industry with three points. -Chemistry
Last Answer : Answer. (a) (i) Rancidity can be prevented by adding antioxidants to food containing fat and oil, e.g. butylated hydroxy anisole is added to butter as antioxidant. (ii) It can be prevented ... cryolite. (iii) Carbonate ores are thermally decomposed to give metal oxide which on reduction give metal.
Description : Most commonly used bleaching agent is – (1) Sodium chloride (2) Alcohol (3) Carbon dioxide (4) Chlorine
Last Answer : (4) Chlorine Explanation: Chlorine is used to disinfect water and is part of the sanitation process for sewage and industrial waste. During the production of paper and cloth, it is used ... in water Bleaching powder is an important and a commonly used bleaching agent prepared from chlorine.
Description : Non-metallic character increases from (1) Magnesium to Barium (2) Potassium to Cesium (3) Oxygen to Selenium (4) Sodium to Chlorine
Last Answer : (4) Sodium to Chlorine Explanation: The elements which lose electrons to form cations are known as metals. Metallic character decreases across a period as we move from left to right.
Description : The most electronegative element among the following is – (1) Fluorine (2) Sodium (3) Chlorine (4) Oxygen
Last Answer : (1) Fluorine Explanation: Electronegativity of the elements using the Pooling Scale is as follows: Fluorine: 3.98, Oxygen: 3.44, Chlorine: 3.16, and Sodium: 0.93. Electronegativity increases down the group and decreases down the period.
Description : What product is formed when electricity is passed throughan aqueous solution of sodium chloride? (1) Sodium and water (2) Sodium oxide (3) Sodium and chlorine (4) Sodium hydroxide
Last Answer : (4) Sodium hydroxide Explanation: When electricity is passed through an aqueous solution of sodium chloride, it gives hydrogen, chlorine and sodium hydroxide as a product.
Description : Write balanced chemical equations for the following word equations: (a) Iron + Chlorine → Iron (III) chloride (b) Magnesium + dil sulphuric acid → Magnesium sulphate + water (c) Magnesium + oxygen → ... oxide (d) Calcium oxide + water → Calcium hydroxide (e) Sodium + chlorine → Sodium chloride
Last Answer : (a) Iron + Chlorine → Iron (III) chloride 4Fe + 3Cl2 → 2F2Cl3 (b) Magnesium + dil sulphuric acid → Magnesium sulphate + water 2Mg + 2H2SO4 → 2MgSO4 + 2H2 (c) Magnesium + oxygen → Magnesium oxide 2Mg ... hydroxide CaO + H2O → Ca(OH)2 (e) Sodium + chlorine → Sodium chloride 2Na + Cl2 → 2NaCl
Description : Most commonly used bleaching agent is (1) Sodium chloride (2) Alcohol (3) Carbon dioxide (4) Chlorine
Last Answer : Chlorine
Description : The most electronegative element among the following is (1) Fluorine (2) Sodium (3) Chlorine (4) Oxygen
Last Answer : Fluorine
Description : 1.12 litre dry chlorine gas at STP was passed over a heated metal when 5.56 g of chloride of the metal was formed. What is the equivalent weight of th
Last Answer : 1.12 litre dry chlorine gas at STP was passed over a heated metal when 5.56 g of chloride of ... formed. What is the equivalent weight of the metal ?
Description : The normal serum value for potassium is a) 3.5-5.5 mEq/L. Serum potassium must be within normal limits to prevent cardiac dysrhythmias. b) 135-145 mEq/L. Normal serum sodium is 135-145 mEq/L. c) 96-106 mEq/L. ... is 96-106 mEq/L. d) 8.5-10.5 mg/dL. Normal total serum calcium is 8.5-10.5mg/dL.
Last Answer : a) 3.5-5.5 mEq/L. Serum potassium must be within normal limits to prevent cardiac dysrhythmias.
Description : What is the healing time for cataract surgery and what must be avoided during this time?
Last Answer : After a cataract surgery the number one thign the person should avoid is bright lights. They will be able to heal in about three weeks after the surgery.
Description : 61. A client with gout asks the nurse what food must be avoided so that the family can provide support. Which food has the highest in purine content and must be excluded from the dietary plan?
Last Answer : D. Liver
Description : Which one of the following is not part of the traditional view of conflict? (a) inevitable ; (b) must be avoided ; (c) indicates malfunctioning ; (d) harmful
Last Answer : (a) inevitable ;
Description : Which of the following is a correct match? (a) Down’s syndrome - 21st chromosome (b) Sickle cell anaemia - X-chromosome (c) Haemophilia - Y-chromosome (d) Parkinson’s disease - X and Y chromosome
Last Answer : a) Down’s syndrome - 21st chromosome
Description : Pick out the correct statements. (1) Haemophilia is a sex-linked recessive disease. (2) Down's syndrome is due to aneuploidy. (3) Phenylketonuria is an autosomal recessive gene disorder. (4) Sickle cell anaemia is an X- ... are correct. (c) (1) and (4) are correct. (d) (2) and (4) are correct.
Last Answer : (b) (1), (2) and (3) are correct.
Description : .A disease caused by an autosomal primary non- disjunction is (a) Klinefelter’s syndrome (b) Turner’s syndrome (c) Sickle cell anaemia (d) Down’s syndrome.
Last Answer : (d) Down’s syndrome.
Description : The most striking example of point mutation is found in a disease called (a) Down’s syndrome (b) sickle cell anaemia (c) thalassaemia (d) night blindness.
Last Answer : (b) sickle cell anaemia
Description : A disease caused by an autosomal primary non- disjunction is : (1) Klinefelter's Syndrome(2) Turner's Syndrome (3) Sickel Cell Anemia (4) Down's Syndrome
Last Answer : (4) Down's Syndrome