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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 5251. |
How would you obtain ethene from ethanol? Give equation. |
| Answer» SOLUTION :`underset("ETHANOL")(C_2H_5OH) OVERSET(H_2SO_4 , 170^@C)(to) underset("ethane")(C_2H_4) + underset("water")(H_2O)` | |
| 5252. |
How would you name the following compounds ? (i) CH_(3)-CH_(2)-Br (ii) H-overset(H)overset(|)C=O (iii) H-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-C-=C-H |
| Answer» SOLUTION :The name of the given COMPOUNDS are (i) Bromoethane, (ii) METHANAL and (III) Hex-1-yne or Hexyne. | |
| 5253. |
How would you name the following compounds ? (i) CH_(3)-CH_(2)-Br (ii) H-overset(H)overset(|)C=O (iii) CH_(3)-CH_(2)-CH_(2)-CH_(2)-C -= CH_(2) |
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Answer» Solution :(i) BROMOETHANE (II) METHANAL (iii) HEXYNE |
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| 5254. |
How would you name the following compounds ? (i) CH_3 - CH_2-Br "" (ii) H-CH=O (iii) H-C=C-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(c)-underset(H)underset(|)overset(H)overset(|)(c)-underset(H)underset(|)overset(H)overset(|)(C)-H |
| Answer» SOLUTION :i] Bromoethane.`""` II]METHANAL. `""` iii] Hexyne. | |
| 5255. |
How would you distinguish experimentally between an alcohol and a carboxylic acid? |
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Answer» Solution :All the carboxylic acids decompose sodium hydrogencarbonate GIVING BRISK effervescence of carbon dioxide gas whereas ethanol does not react with sodium hydrogencarbonate. Experiment: (i) Take two test tubes, label them as A and B. (ii) Take about 0.5g of sodium hydrogencarbonate `(NaHCO_(3))` in each test tube. (iii) ADD 2 mL of ethanol in test tube A and 2 mL of ETHANOIC ACID in test tube B. (iv) We can observe the gas bubbles in test tube B. No such bubbles are seen in test tube A. Pass the gas produced in test tube B through lime water taken in another test tube. (v) We will find that lime water turns milky. It is a test for carbon dioxide. Hence, this experiment proves that when ethanoic acid reacts with sodium hydrogencarbonate then carbon dioxide gas is produced with an effervescence (a rapid evolution of gas bubbles). Ethanol does not react with `NaHCO_(3)`. |
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| 5256. |
How would you distinguish between powder and washing soda by heating ? |
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Answer» Solution :The chemical formula of baking POWDER is sodium hydrogencarbonate `(NaHCO_3)` , whereas , that of WASHING soda is sodium carbonate `(Na_(2)CO_(3).10H_(2)O)`. Sodium hydrogencarbonate on HEATING gives `CO_2` gas which will turn lime water milky whereas no such gas is obtained from sodium carbonate. `2NaHCO_(3)overset("Heat")rarrNa_(2)CO_(3)+H_(2)O+CO_(2)` `Na_(2)CO_(3).10H_(2)Ooverset("Heat")rarrNa_(2)CO_(3)+10H_(2)O` |
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| 5257. |
How would you distinguish experimentally between an alcohol and a carhoxylic acid? |
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Answer» SOLUTION :(i) We can distinguish between an alcohol and a carboxylic acid on the basis of their REACTION with sodium carbonate and sodium HYDROGEN arbonate Carboxylic acids reacts with sodium carbonate and sodium hydrogen carbonate to evolve `CO_(2)` gas that TURNS lime water MILKY. Alcohol, on the other hand, do not react with sodium carbonate and sodium hydrogen carbonate. (ii) Alcohol reacts with sodium metal to produce hydrogen gas with rapid effervescence. On the other hand, carboxylic acid does not show this type of chemical reaction with sodium metal. |
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| 5258. |
How would you distinguish between an alcohol and acetic acid ? |
| Answer» Solution :Acetic acid GIVES EFFERVESCENCE with sodium hydrogencarbonate, but ALCOHOL does not . | |
| 5259. |
How would you distinguish between baking powder and washing soda by heating ? |
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Answer» Solution :The chemical formula of baking powder is SODIUM hydrogencarbonate `(NaHCO_(3))` whereas, that of WASHING soda is sodium carbonate `(Na_(2)CO_(3).10H_(2)O)`. Sodium hydrogencarbonate on heating gives `CO_(2)` gas which will turn lime water milky whereas no such gas is OBTAINED from sodium carbonate. `2NaHCO_(3) - "Heat" rarr Na_(2)CO_(3) + H_(2)O + CO_(2)` `Na_(2)CO_(3).10H_(2)O rarr "Heat" rarr Na_(2)CO_(3) + 10H_(2)O` |
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| 5260. |
How would you bring about the following conversions? Name the process and write the reaction involved. (a) Ethanol to ethene. (b) Propanol to propanoic acid. |
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Answer» SOLUTION :(a) By the dehydration of ethanol in the presence of concentrated `H_(2)SO_(4)`. `CH_(3)CH_(2)OH underset("HEAT")overset("Conc. "H_(2)SO_(4)) to CH_(2)=CH_(2)+H_(2)O` (B) By the oxidation of propanol using oxidising AGENT such as alkaline `KMnO_(4)`. `CH_(3)CH_(2)CH_(2)OH underset("Heat") overset("ALK. "KMnO_(4)) to CH_(3)CH_(2)COOH+H_(2)O` |
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| 5261. |
How would the tendency to lose electrons change as you go i] from left to right across a period ii] down a group |
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Answer» SOLUTION :Tendency to lose electron i] DECREASES with increase in atomic number in a period from left to RIGHT ACROSS period ii] Will increases down a group |
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| 5262. |
How would the tendency to gain electrons change as you go from left to right across a period ? |
| Answer» Solution :As we go from LEFT to RIGHT across a period, the tendency to GAIN ELECTRONS INCREASES. | |
| 5263. |
How would the tendency to gain electrons change as you go down a group ? |
| Answer» Solution :As we GO down a GROUP, the TENDENCY to GAIN ELECTRONS decreases. | |
| 5264. |
How would tendency to gain electrons change as you go down a group ? |
| Answer» SOLUTION :It is expected to decrease since atomic size increases down the group and the TENDENCY of the ELEMENT to GAIN electrons decreases. | |
| 5265. |
How will your demonstrate that the ionic compounds do not conduct electricity in the solid state and can do so in solution. |
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Answer» Solution :1. In a glass beaker, take small amount of solid sodium chloride. 2. Dip two GRAPHITE rods (electrodes) in the solution. 3. Connect these rods to a battery through a bulb and a switch. 4. Switch on the battery. The bulb will not glow. This show that no current has passed through the solid sodium chloride. 5. Now, add some water to the salt so that it may dissolve. 6. Repeat the operation. The bulb will immediately glow showing that current has passed through the salt solution. Explanation. Sodium chloride (NaCl) is a crystalline solid and the current is carried by the mobility (MOVEMENT) of ions. Since the ions do not MOVE in the solid state, the salt is not conducting. In aqueous solution, both `Na^(+)` and `Cl^(-)` ions can move and the salt will be conducting in the solution. That is why the bulb glows. 
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| 5266. |
How will you test to identify saturated and unsaturated compounds? |
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Answer» Solution :Test to identify saturated and unsaturated COMPOUNDS: TAKE the given sample solution in a test TUBE. Add a few drops of bromine water and observe any charactersitic CHANGE in colour. If the given compound is unsaturated, it will decolourise bromine water. Saturated compounds do not decolourise bromine. 
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| 5267. |
How will you test the gas evolved ? |
| Answer» Solution :When a BURNING matchstick is brought NEAR the HYDROGEN gas, it BURNS with a popping sound. | |
| 5268. |
How will you test for the gas which is liberated when hydrochloric acid reacts with an active metal? |
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Answer» SOLUTION :When an active METAL like Zn REACTS with HCl, the gas produced burns with a POP sound which indicates that it is hydrogen gas. `Zn(s)+2HCL(aq)rarrZnCl_(2)(s)+H_(2)(g)` |
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| 5269. |
How will you test for the gas which is liberated when hydrochloric acid reacts with an active metal ? |
| Answer» Solution :BRING a BURNING match STICK near the gas. It burn with POP sound showing that the liberated gas is Hydrogen. | |
| 5270. |
How will you test a gas which is liberated when hydrochloric acid reacts with an active metal ? |
| Answer» SOLUTION :The gas gives a pop SOUND when a BURNING candle is brought NEAR it | |
| 5271. |
How will you prove that zinc is more reactive than copper? |
| Answer» Solution : Take strips of zinc and COPPER and two test tubes with copper sulphate and zinc sulphate solution. Add zinc STRIP in copper sulphate solution and copper strip in zinc sulphate solution. OBSERVATION : In the test tube with zinc strip in copper sulphate solution shows that BLUE colour of copper sulphate solution fades. The other test tube will not show any change. This proves that zinc is more reactive than copper. | |
| 5272. |
How will you prove that a given salt is a carbonate of a metal? |
| Answer» Solution :To SALT add few drops of dilute HCl or `H_2SO_4`. If colourless gas is evolved with BRISK effervescence and on PASSING it through lime water, the lime water turns milky, the gas is `CO_2` and salt is a carbonate of METAL. | |
| 5273. |
How will you predict the nature of chemical bonds using electronegativity values? |
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Answer» Solution :(i) If the DIFFERENCE in electronegativity between the two ELEMENTS is 1.7, the bond has 50% ionic character and 50% COVALENT character. (ii) If the difference is less than 1.7, the bond is considered to be covalent. (iii) If the difference is greater than 1.7, the bond is considered to be ionic. |
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| 5274. |
How will you indicate the following effects in a chemical equation ? (a) A solution made in water (b) Endothermic reaction |
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| 5275. |
How will you identify the copper sulphate, iron sulphate and barium sulphate in the laboratory? |
| Answer» Solution : Above given SUBSTANCES can be identified by their colours. For example, the colour of iron (II) SULPHATE is green, the colour of iron (III) sulphate is YELLOWISH brown. The colour of copper (II) sulphate is blue, and the WHITE colour salt is BARIUM sulphate. | |
| 5276. |
How will you extract aluminum from its ore? |
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Answer» Solution :The extraction of aluminum from bauxite involves two steps: (1) Conversion of bauxite into alumina - Baeyer.s Process The conversion of bauxite into alumina involves the following steps: Bauxite ore is finely ground and heated under pressure with a solution of concentrated caustic soda solution at150 ° C to obtain sodium meta aluminate.On diluting sodium meta aluminate with water, a precipitate of aluminum hydroxide is formed The precipitate is filtered, washed, dried and ignited at `1000^(@)C` to get alumina. `2Al(OH)underset(Delta)overset(1000^(@)C)toAl_(2)O_(3) + 3H_(2)O` (ii) Electrolytic reduction of alumina - Hall.s Process Aluminum is produced by the electrolytic electrolytic process of manufacturing aluminum reduction of fused alumina`(Al_(2),O_(3))` in the electrolytic cell.Cathode: Iron tank linked with graphite Anode: A bunch of graphite rods suspended in molten electrolyte. Electrolyte: PURE alumina + molten CRYOLITE carbon cathode lining + fluorspar (fluorspar lowers the fusion TEMPERATURE of electrolyte) Temperature: 900 - 950 ° C Voltage used: 5-6 V Overall reaction: `2 Al_(2)O_(3)rightarrow4Al+3O_(2)uparrow`Aluminum is DEPOSITED at the cathode and oxygen gas is liberated at the anode.Oxygen combines with graphite to form `CO_(2)` 
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| 5277. |
How will you enhance the rate of decomposition of potassium chlorate? |
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Answer» Solution :On heating potassium chlorate.It decomposes into potassium chloride and oxygen gas,but at a SLOWER rate.If maganese dioxide is added,it increases the REACTION rate. `2KClO_(3)underset(Delta)OVERSET(MnO_(2))to2KCl+3O_(2)uarr` Here `MnO_(2)` is catalyst,Therefore addition of `MnO_(2)` enhance the rate of DECOMPOSITION of potassium chlorate. |
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| 5278. |
How will you distinguish between combination and decomposition reactions? |
Answer» SOLUTION :
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| 5279. |
How will you distinguish between baking powder and washing soda by heating? |
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Answer» Solution :On heating beaking poweder, `CO_2` gas is liberated which turns LIME WATER MILKY `2NaHCO_(3) OVERSET("Heat")rarr Na_2CO_3+H_2O+CO_2` No gas is liberated on heating washing soda. `Na_(2)CO_(3),10H_(2)O overset("Heat")rarr Na_(2)CO_(3)+ 10 H_(2)O` |
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| 5280. |
How will you differentiate sodium metal and zinc metal given in the test tubes in the laboratory ? You are advised not to touch any of the metals. Identify the type of reaction used. |
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Answer» Solution :First of all, I add WATER in both the test tubes and observe the reaction. The test TUBE in which vigorous reaction takes PLACE contains Na metal, which reacts and forms `H_(2)`(g) gas in the test tube. `2NA+ 2H_(2)O to 2NaOH+ H_(2)` This iscombination and exothermic |
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| 5281. |
How will you differentiate saturated and unsaturated hydrocarbon compounds? |
| Answer» Solution :`{:("S.No.","Saturated hydrocarbon","Unsaturated hydrocarbon"),(1.,"Saturated hydrocarbon undergoes substitution REACTIONS in the presence of sunlight.","Unsaturated hydrocarbon undergoes ADDITION reaction with hydrogen in the presence of nickel CATALYST."),(2.,underset("METHANE")(CH_(4))+Cl_(2)overset("Sunlight")rarrunderset("METHYL chloride")(CH_(3)Cl)+HCl,underset("Ethene"(CH_(2)=CH_(2))overset(H_(2)//Ni)rarrunderset("Ethane")(CH_(3)-CH_(3)))),(3.,"Saturated hydrocarbon does not decolourise bromine water.","Unsaturated hydrocarbon decolourise sbromine water."):}` | |
| 5282. |
How will you differentiate between metals and non-metals by the number of valence electrons? |
| Answer» Solution : ELEMENTS which have 1, 2 or 3 valence electrons are METALS and those which have 4, 5, 6 or 7 valence electrons are non-metals. | |
| 5283. |
HowwillyoudeterminetheatomicityofgasesusingAvogadro'shypothesis ? |
Answer» Solution :TheAtomicityof anelementcan bederivedusingAvogadro'shypothesis. LETUS considerthefollowingequation  Accordingto Avogadro'slaw , 1volumeof anygasoccup'n'numberof molecules.  ifn=1 then  (i )1 moleculeof hydrogenchloridegasismadeupof `1//2`moleculesofhydrogenand`(1)/(2)`Moleculeof chlorine (ii)But1 moleculeof hydrogenchloridecontainsoneatomofhydrogenand 1 atomofchlorine (III )Hence`(1)/(2) `moleculeof hydrogen =1 atomof hydrogen (IV )OR1 molecule ofhydrogen=2 atoms ofhydrogen (V )SO theatommicityofhydrogenis2 , andmolecularformulais `H_(2) ` similarly , `(1)/(2) ` Molecule ofclorine=1atomofchlorine1 moleculeofchlorine =2atomsofchlorineso theatomicityof chlorineis 2 ,and itsmolecularformulais `Cl_(2)`. |
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| 5284. |
HowwillyoudeducedatomicityofHomoatomicmolecule ? |
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Answer» SOLUTION :(I )For anyhomoatomicmoleculeatomicityand bededucedusing the formula . (II )ATOMICITY= `(" MolecularMass ")/( "ATOMICMASS ")` |
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| 5285. |
How will you convert ethanoic acid into methane? Explain with the help of equations of the reactions involved. |
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Answer» Solution :`underset("Ethanoic acid")(CH_(3)COOH)+underset("hydroxide")underset("SODIUM")(NaOH)to underset("Sodium ethanoate")(CH_(3)COONa)+underset("Water")(H_(2)O)` Then, sodium ethanoate is HEATED with SODALIME to get methane. `underset("Sodium ethanoate")(CH_(3)COONa)+underset(("from sodalime"))underset("Sodium hydroxide")(NaOH) to underset("Methane")(CH_(4))+underset("CARBONATE")underset("Sodium")(Na_(2)CO_(3))` |
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| 5286. |
How will you convert copper into copper earbonate? |
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Answer» Solution :Copper REACTS with OXYGEN in the PRESENCE of CO, and moisture to give copper carbonate `2Cu+O_(2)+CO_(2)+H_(2)OrightarrowCuCO_(3).CU(OH)_(2)` (copper Carbonate) |
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| 5287. |
How will you classify hydrocarbons ? |
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Answer» Solution :Hydrocarbons are classifiedinto THREE classes such as : (i) Alkanes : These are hydrocarbons which CONTAIN only singlebonds.They are represented by the GENERAL formula `C_nH_(2n+2)`(where n=1,2,3,.........). (ii) Alkenes : The hydrocarbonswhich contain one or more C=C bonds are calledalkenes . These are unsaturatedcompounds . They are represented by the general formula `C_nH_(2n)`. Ex: Ethylene `(C_2H_4)` Hydrocarbonsare organiccompounds THATARE made of only hydrogenand carbon atoms.They are found in many palces , including crude OIL and natural gas . |
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| 5288. |
How will you bring about the following conversions : (i) Ethanoic acid to ethanol (ii) Ethanol to ethanal ? |
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Answer» Solution :(i) Ethanoic acid to ethanol `CH_(3)COOH underset("Reduction")overset(LiAlH_(4))RARR CH_(3)CH_(2)OH]` (ii) Ethanol to ETHANAL `CH_(3)CH_(2)OH underset(CrO_(3)//CH_(3)COOH)overset((O))rarr CH_(3)CHO` |
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| 5289. |
How will the tendency to gain ele ctr o ns change as we go from left to right across a pe riod? Why? |
| Answer» Solution :Tendency to gain e lectron s increase s from leftto right in a PERIOD becau SE at o m ic SIZE goe s ondecreasing and EFFECTIVE nuclear CHARGE mcrease s. | |
| 5290. |
How will this tendency change in a period ? |
| Answer» SOLUTION :As we MOVE from left to right in a period, the TENDENCY to LOSE electrons decreases. | |
| 5291. |
How will an organism be benefited if it reproduces through spores? |
| Answer» SOLUTION :Large number of spores are produced in one sporangium. Spores are distributed easily by AIR to FAR off places to avoid COMPETITION at one place. Spores are covered by thick walls to prevent dehydration under unfavourable conditions. | |
| 5292. |
How were transition elements placed in 0 Mendeleev's Periodic Table and (ii) Modern Periodic Table? |
| Answer» Solution :Transition elements were placed: (i) along with other elements in Mendeleev.s periodic table and (II) SEPARATELY in the middle in the MODERN Periodic Table. | |
| 5293. |
How werethe positions of different isotopes decided in modern periodic table? |
| Answer» Solution :All the isotopes of an element have same atomic numbers. In modem PERIODIC table, the elements have been allotted places based on their atomic numbers, Therefore, all the isotopes of an element have been ASSIGNED the same POSITION in the modern periodic table | |
| 5294. |
How were the positions of isotopes of various elements decided in the modern periodic table ? |
| Answer» Solution :In the modern periodic table, POSITIONS of isotopes of DIFFERENT elements are not FIXED separately. Since the various isotopes of an element have the same atomic number, they are assigned the same POSITION in the modern periodic table. | |
| 5295. |
How were the positions of cobalt and nickel resolved in the modern periodic table ? |
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Answer» Solution :( 1 ) In modern periodic table, elements are arranged in increasing ORDER of their atomic numbers. (2) The atomic NUMBER of cobalt and nickel are 27 and 28 RESPECTIVELY. Hence, on the basis of increasing order of their atomic numbers, cobalt is placed in group 9 and nickel is placed in group 10. |
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| 5296. |
How were the positions of cobalt and nickel resolved in the Modern Periodic Table? |
| Answer» Solution :Cobalt has ATOMIC NUMBER 27 and atomic MASS 58.9 while Nickel has atomic number 28 and atomic mass 58.7. In Mendeleev.s Periodic Table in which elements are ARRANGED in increasing order of their atomic masses, Cobalt was placed before Nickel violating the periodic law. In MODERN Periodic Table in which elements are arranged in increasing order of their atomic numbers, Cobalt is rightly placed before Nickel. | |
| 5297. |
How washing soda is obtained from baking soda ? Write the balanced chemical equations. |
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Answer» Solution :`2NaHCO_(3)OVERSET("heat")rarr Na_(2)CO_(3) + CO_(2)uarr + H_(2)O` BAKING SODA on heating gives sodium CARBONATE which on crystallisation from AQUEOUS solution gives washing soda. `Na_(2)CO_(3) + 10H_(2)O rarr Na_(2)CO_(3).10H_(2)O`. |
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| 5298. |
How to write and name the molecular formula by knowing the number of carbon atoms ? |
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Answer» Solution :Molecular FORMULA = WORD root + SUFFIX To CALCULATE molecular formula put the value of n . |
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| 5299. |
How the following substances will dissociate to produce ions in their solution ? (i) Hydrochloric acid(iv) Sodium Hydroxide (ii) Nitric acid (v) Potassium Hydroxide (iii) Sulphuric acid (vi) Magnesium Hydroxide |
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Answer» Solution :Dissociation of various compounds in their solution : (i) Hydrochloric acid (HCl) (aq) `HCl(aq) rarr H^(+) (aq) + Cl^(-)(aq)` (ii) Nitric acid `(HNO_(3))` (aq) `HNO_(3)(aq) rarr H^(+)(aq) + NO_(3)^(-)(aq)` (iii) Sulphuric acid `(H_(2)SO_(4))` (aq) `H_(2)SO_(4)(aq) rarr 2H^(+) (aq) + SO_(4)^(2-)(aq)` (iv) Sodium Hydroxide - (NaOH) (aq) `NaOH(aq) rarr Na^(+)(aq) + OH^(-)(aq)` (v) Potassium hydroxide KOH(aq) `KOH(aq) rarr K^(+)(aq) + OH^(-)(aq)` (vi) Megnesium Hydroxide `Mg(OH)_(2)` (aq) `Mg(OH)_(2)(aq) rarr Mg^(2+) (aq) + 2OH^(-)(aq)` |
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| 5300. |
How the atoms of sulphur are arranged in its molecule ? Show by a diagram . |
Answer» SOLUTION :SULPHUR MOLECULE is REPRESENTED by ` S_(8)` 
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