InterviewSolution
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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.
| 6301. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to the instruction given below : Statement - 1 : 2H_(2)O_(2) rarr2H_(2)O+O_(2) is Decomposition reaction (Redox). Statement - 2 : Oxygen has -2 oxidation state in H_(2)O |
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Answer» If both the STATEMENTS are TRUE and Statement-2 is the CORRECT EXPLANATION of the statement-1 |
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| 6302. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to the instruction given below : Statement - 1 : CaCO_(3) rarr CaO + CO_(2) is not redox reaction. Statement - 2 : C, Ca, O do not change their oxidation number in the reaction. |
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Answer» If both the STATEMENTS are TRUE and Statement-2 is the CORRECT EXPLANATION of the statement-1 |
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| 6303. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to the instruction given below : Statement - 1 : Oxidation also occurs when decrease in electron density is observed. Statement - 2 : Oxidation is gain of electro-positive element. |
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Answer» If both the STATEMENTS are TRUE and Statement-2 is the CORRECT explanation of the statement-1 |
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| 6304. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to the instruction given below : Statement - 1 : C + O_(2)rarr CO_(2) , carbon get oxidised. Statement - 2 : Gain of Hydrogen is reduction. |
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Answer» If both the STATEMENTS are True and Statement-2 is the CORRECT explanation of the statement-1 |
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| 6305. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to the instruction given below : Statement - 1 : For the reaction Zn +Cu^(2+) rarr Zn^(2+)+Cu, E_("cell") "is"+ve. Statement - 2 : For standard Hydrogen electrode E^(@) = 0 |
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Answer» If both the statements are TRUE and Statement-2 is the CORRECT explanation of the statement-1 |
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| 6306. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to the instruction given below : Statement - 1 : Oxygen has zero oxidation state in O_(2). Statement - 2 : Element in their elemental form have zero oxidation state. |
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Answer» If both the STATEMENTS are TRUE and Statement-2 is the CORRECT EXPLANATION of the statement-1 |
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| 6307. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to instruction given below : Statement - 1 : In HF, the oxidation state of 'F' is –1 Statement - 2 : 'F' being most electronegative, will have -1 oxidation in its compound. |
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Answer» If both the STATEMENTS are TRUE and Statement-2 is the CORRECT EXPLANATION of the statement-1 |
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| 6308. |
Each question contain statement-1 (Assertion) and statement-2 (Reason) Examine the statements carefully and work the correct answer according to the instruction given below : Statement - 1 : Oxidation state of Oxygen in H_(2)O_(2) is –1. Statement - 2 : H_(2)O_(2) has peroxide linkage. |
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Answer» If both the STATEMENTS are TRUE and Statement-2 is the CORRECT EXPLANATION of the statement-1 |
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| 6310. |
Each of the following oxide dissolves in water to give an aqueous solution which turns red litmus blue except |
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Answer» MgO `CO_(2)` is a non metal oxide, acidic in nature. |
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| 6311. |
Each of the following hydrocarbon belongs to an alkane series except |
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Answer» `C_(3)H_(8)` `C_(4)H_(6)` belongs to alkyne series as it satisfies the formula `C_(n)H_(2n-2)` |
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| 6312. |
Each member of the homologous series differ from the succeeding member by a common difference of…………………and by a molecular mass of…………………. |
| Answer» SOLUTION :`CH_(2)`, 14 AMU | |
| 6314. |
Dyes are added to colour the alcohol blue. This is called denatured alcohol. |
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Answer» |
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| 6315. |
During which reaction is dihydrogen gas not produced under normal conditions? |
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Answer» METAL + dilute SULPHURIC ACID |
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| 6316. |
During white washing,………….reacts slowly with carbon dioxide in air to form a thin layer of………on the walls. |
| Answer» SOLUTION :CALCIUM HYDROXIDE,calcium CARBONATE | |
| 6317. |
During the reaction of some metals with dilute hydrochloric acid, following observations were made. (i) The temperature of the reaction mixture rises when aluminium (Al) is added. (ii) The reaction of sodium metal is found to be highly explosive. (iii) Some bubbles of a gas are seen when lead (Pb) is reacted with the acid. Explain these observations giving suitable reasons. |
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Answer» SOLUTION :(i) The temperature of the reaction mixture rises when aluminium is added because it is an exothermic reaction. (ii) Reaction of sodium metal is found to be HIGHLY explosive because it is an exothermic reaction. (iii) When lead is TREATED with HYDROCHLORIC acid, bubbles of hydrogen gas are EVOLVED. `Pb(s)+2HCl(aq)rarrPbCl_(2)(aq)+H_(2)(g)` |
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| 6318. |
During the reaction of some metals with dilute hydrochloric acid, following observations were made. (a) Silver metal does not show any change (b) The temperature of the reaction mixture raises when aluminium is added. (c) The reaction of sodium metal is found to be highly explosive. (d) Some bubbles of a gas are seen when lead reacts with the acid. Explain these observations giving suitable reasons. |
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Answer» Solution :(a) Silver is less reactive than hydrogen. (B) The REACTION is EXOTHERMIC. (c) SODIUM is highly reactive. (d) Lead, more reactive than hydrogen , reacts with HCl and displaces hydrogen from its solution. |
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| 6319. |
During the quenching of steel, it is plunged eitherintor a water bath or in an oil bath. Explain why different baths are used. |
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Answer» Solution :(i) Comparing cooling properties of oil and water. (ii) Comparison of the property related to rise in TEMPERATURE of oil and water. (III) EFFECT of property on the rate of cooling of steel. (IV) Relation between the rate of cooling and the change in the properties of steel. |
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| 6320. |
During the preparation of soap the addition of common salt allows the precipitation of soap . Expalin the principle involved (Soap is the sodium saltof carboxylic acid ). |
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Answer» SOLUTION :The addition of comon salt RESULTS in the addition of `Na^(+)` ions. Equilibriumexist between sodium and stearate ions. The addition of `Na^(+)` ions shifts the equilibrium TOWARDS LEFT thus sodium stearte precipitates. `RCOO^(-)Na^(+) HARR RCOO^(-)+Na^(+)`. |
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| 6321. |
During the preparation of hydrogen chloride gas on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to |
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Answer» ABSORB the EVOLVED gas |
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| 6322. |
During the preparation of hydrogen chloride gas on a humid day the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to |
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Answer» ABSORB the evolved gas |
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| 6323. |
During the oxidation of ethanol with acidified K_(2)Cr_(2)O_(7) the………………..colour changes to………………colour. |
| Answer» SOLUTION :ORANGE, GREEN | |
| 6324. |
During the melting of ice, temperature . |
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Answer» decreases |
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| 6325. |
During the formation of sodium chloride from its constituents, |
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Answer» Na undergoes oxidation and acts as an oxidizing AGENT  During the FORMATION of NaCl, Na undergoes oxidation and Cl undergoes reduction. Hence, Na is the reducing agent and Cl is the oxidizing agent. |
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| 6326. |
During the electrolysis of water containing dilute sulphuric acid |
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Answer» sulphate IONS are oxidised at anode and HYDROGEN ions are reduced at cathode . |
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| 6327. |
During the electrolysis of silver nitrate using copper anode, the colour changes to blue and the intensity of the colour increases. Explain with the help of electrochemical series. What would you observe if ZnSO_(4) is taken instead of AgNO_(3) ? |
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Answer» Solution :(i) COMPARISON of electropositively of COPPER and silver. (ii) Identification of the product obtained at the ELECTRODE. (iii) Nature of the anode. (IV) Reaction that takes PLACE between the anode and the electrolyte. (v) Ions responsible for blue colour |
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| 6328. |
During the electrolysis of molten lead bromide , which of the following takes place ?Bromine is released at the cathodeLead is deposited at the anodeBromine ions gain electronsLead is deposited at the cathode |
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Answer» BROMINE is RELEASED at the cathode |
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| 6329. |
During the electrolysis of molten lead bromide : |
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Answer» lead ions are discharged at anode |
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| 6330. |
During the electrolysis of hot aqueous solution of lead bromide (a) lead ions are discharged at cathode (b) bromine gas is liberated at cathode (c) lead is deposited at cathode (d) hydrogen gas is liberated at cathode |
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Answer» lead ions are discharged at CATHODE |
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| 6331. |
During the electrolysis of dilute H_(2)SO_(4) oxygen is liberated at anode . Give reason . |
| Answer» Solution :Because the `OH^(-)` ION is oxidised as `4OH^(-) to 2H_(2)O +O_(2) +4E^(-)` | |
| 6332. |
During the electrolysis of acidifiedsolutionof copper sulphate , the Cu^(2+) ionsmigrate towards _______ . |
| Answer» SOLUTION :CATHODE | |
| 6333. |
During the electrolysis of copper (II) sulphate solution using platinum as cathode and carbon as anode : What do you observe at the cathode and at the anode ? |
| Answer» SOLUTION :Copper is DEPOSITED at the CATHODE , and `O_(2)` is LIBERATED at the anode . | |
| 6334. |
During the determination of the boiling point of water the thermometer is kept |
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Answer» DIPPED in water |
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| 6335. |
During metallurgy of iron its, ore coke and limestone are added to the blast furnace. (a) What is the role of limestone? (b) Identify the reducing agent in the extraction of ironduring the above process. (c) Identifly slag formed during the above process. (d) What are the different gases liberated in this process? |
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Answer» Solution :(a) Limestone `(CaCO_(3))` undergoes thermal decomposition and GIVES CaO and `CO_(2)`. CaO acts as a flux. (B) Carbon monoxide acts as a reducing agent: `FeO+COtoFe+CO_(2)` `Fe_(2)O_(3)+3COto+3CO_(2)` (c) CaO REACTS with the impurity `SiO_(2)` and forms the slag `CaSiO_(3)`: `CaO+SiO_(2)toCaSiO_(3)` (d) `C+O_(2)toCO_(2)(g)` `CO_(2)+Cto2CO(g)` `CaCO_(3)toCaO+CO_(2)(g)` `FeO+COtoFe+CO_(2)(g)` `Fe_(2)O_(3)+3COto2Fe+3CO_(2)(g)` `CO_(2)` gas is liberated. CO gas is FORMED, but takes part in the process of erduction of `Fe_(2)O_3)` and forms `CO_(2)`. |
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| 6336. |
During isothermal expansion of an ideal gas, there is no change in internal energy. |
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Answer» |
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| 6338. |
During extraction of metals, electrolytic refining is used to obtain pure metals. (i) Which material will be used as anode and cathode for refining of silver metal by this process? (ii) Suggest a suitable electrolyte also. (iii) In this electrolytic cell, where do we get pure silver after passing electric current. |
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Answer» SOLUTION :(i) Anode: Impure silver CATHODE: Pure silver (ii) ELECTROLYTE: Silver salt, such as `AgNO_3,AgCl` ETC (iii) we get pure silver at cathode. |
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| 6339. |
During electrolysis of water the amount of gas collected in one of the test tubes is double the amount collected in the other why ? |
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Answer» Solution :During electrolysis of water, the water molecule decomposes to give HYDROGEN and oxygen gas. In a water molecule hydrogen and oxygen are present in `2:1` ratio, HENCE the amount of hydrogen is double the amount of oxygen. `2H_(2)Ooverset("electric CURRENT")(to)2H_(2)+O_(2)`. |
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| 6340. |
During electrolysis of water a few drops of sulphuric acid is added into water. Why? |
| Answer» Solution :PURE water is a bad conductor of electricity. By adding a few DROPS of sulphuric ACID, it becomes a GOOD conductor of electricity. | |
| 6341. |
During electrolysis of molten PbBr_(2), _____ fumes are liberated at the anode. |
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Answer» |
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| 6342. |
Give appropriate scientific reasons for the following statements : During electrolysis of molten lead bromide, graphite anode is preferred to other electrodes |
| Answer» SOLUTION :GRAPHITE is not attacked by bromine `(Br_(2))` | |
| 6343. |
During electrolysis of brine, a gas .G. is liberated at anode. When this gas .G. is passed through slaked lime, a compound .C. is formed which is used for disingecting drinking water. (i) Write formula of .G. and .C.. (ii) State the chemical equation involved. (iii) What is common name of compound .C.? Give its chemical name. |
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Answer» Solution :(i) FORMULA of G is `Cl_(2)` Formula of C is `CaOCl_(2)` (ii) `Ca(OH)_(2)+Cl_(2) to CaOCl_(2)+H_(2)O` (iii) Bleaching POWDER. Calcium OXYCHLORIDE. |
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| 6344. |
During electrolysis of aqueous copper sulphate solution using platinum electrodes, the blue colour of the electrolytic solution fades and towards the end of the process bubbles appear at the cathode. Why ? Also comment on the change in pH of solution due to electrolysis |
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Answer» Solution :Dissociation of electrolyte `CuSO_(4) rarr CU^(2+) + SO_(4)^(2-)` `H_(2)O rarr H^(+) + OH^(-)` Cathode : `Cu^(2+)+ 2e^(-) rarr Cu` `Cu^(2+)` discharge in PREFERENCE to `H^(+)` due to LOW discharge potential. Due to this the blue colour of the solution fades as `Cu^(2+)` ions gradually migrate or discharge at cathode and as the electrolyte or whole `Cu^(2+)` ions are exhausted, `H^(+)` ions get discharged and are LIBERATED as `H_(2)` gas at the cathode. `:.` Bubbles appear at cathode. `H^(+) + e^(-) rarr H` `H + H rarr H_(2)` In the beginning `OH^(-)` ions get discharged at ANODE and `H^(+)` ions remain in the solution. Therefore, pH of the solution decreases. Once all `Cu^(+2)` ions are consumed, `H^(+)` ions start getting discharged at cathode. Therefore, pH of the solution increases. |
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| 6345. |
During electrolysis of an aqueous solution of sulphuric acid between platinum electrodes , two types of anions migrate towards anode but one of them is discharged (oxidised ). Name of the main product of the discharge of anion at anode and write the anode reaction . |
| Answer» SOLUTION :` 4OH^(-) to UNDERSET ("OXYGEN") (2H_(2)O) + O_(2) +4e^(-)` | |
| 6346. |
During electrolysis of an aqueous solution of sulphuric acid between platinum electrodes, two types of anions migrate towards anode but only one of them is discharged. Name the product at the cathode and write the reaction. |
| Answer» Solution :`2H^(+) + 2e^(-) to UNDERSET (" HYDROGEN") (H_(2))` | |
| 6347. |
During electrolysis of an aqueous solution of sulphuric acid between platinum electrodes , two types of anions migrate towards anode but one of them is discharged (oxidised ). Name the anion which is dischargedat the anode . |
| Answer» SOLUTION :`OH^(-)` | |
| 6348. |
During electrolysis of an aqueous solution of sulphuric acid between platinum electrodes , two types of anions migrate towards anode but one of them is discharged (oxidised ). Name these two anions . |
| Answer» SOLUTION :`OH^(-) and SO_(4)^(2-)` | |
| 6349. |
During chemical changes……..are formed and these changes are more ………..than physical changes |
| Answer» SOLUTION :NEW PRODUCTS,PERMANENT | |
| 6350. |
During an electrolysis , the cations are discharged at cathode .This is called reduction Name two cations which will not be reduced in the presence of hydrogen ions . |
| Answer» SOLUTION :`ZN^(2+) and FE^(2+)` | |