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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.
| 2401. |
Waste metal items can be recycled back to make useful things. |
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| 2402. |
Which one of Na, Mg , Fe , and Cu has least tendency to form ions ? |
| Answer» ANSWER :D | |
| 2403. |
Which of the following is not a thermoplastic polymer ? |
| Answer» ANSWER :D | |
| 2404. |
When a piece of sodium metal is dipped into acetic acid, a colourless, odourless and inflammable gas is produced. The gas is |
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Answer» OXYGEN |
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| 2405. |
What is cinnbar ? How is a metal extracted from cinnabar ? Explain briefly. |
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Answer» Solution :Cinnabar (HgS) is an ore of Mercury. The metals being LESS reactive can be obtained by REDUCTION of their oxides of metals by heating alone. So, when Cinnabar is heated in air, it first CHANGES into its oxide and then into mercury METAL. `{:(2HgS(s)+3O_(2)(g),overset("Heat")rarr,2HgO(s),+,2SO_(2)(g)),("(Cinnabar)(from air)",,"Mercury oxide",,"Sulphuric dioxide"),(2HgO(s),overset(Delta)rarr,2Hg(l),+,O_(2(g))),("Mercuric (II) oxide",,"Mercury metal",,"Oxygen"):}` |
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| 2406. |
The structural formula of an organic compound is given below: CH_3-CH_2-O-CH_3 Identify the functional group present in this compound? |
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| 2407. |
What role does methanol play when it is mixed with ethanol ? |
| Answer» SOLUTION :Methanol is poisonous. It MAKES ethanol UNFIT for drinking. | |
| 2408. |
Where do you think should hydrogen be placed in the Modern Periodic Table? |
| Answer» Solution :The modem periodic table is based on the atomic numbers of the ELEMENTS and also upon their electronic distribution ALKALI metals as WELL as hydrogen have one electron in their VALENCE shell. Therefore, hydrogen should be placed in the group of alkali metals. However, it has been assigned a separzte POSITION and is not a member of the group of alkali metals since it is a non-metal. | |
| 2409. |
What is the effect of Cu on the ZnAl alloys? |
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Answer» Solution :(i) MECHANICAL properties of SUBSTANCE. (ii) TYPE of bond present in metal. (iii) Change in the type of bond during the FORMATION of alloy. (iv) Effect of change in the type of bond on the PHYSICAL of the metal. |
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| 2410. |
Which among the following elements has the largest atomic radii? |
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Answer» Na |
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| 2411. |
Which of the following statements is (are) correct about the following reaction ?2Pbo(s) + C(s) to 2Pb(s) + CO_(2) (g) |
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Answer» PbO is being oxidised . |
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| 2412. |
Which pair following elements of the following is likely tohave similar chemical behaviour ? |
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Answer» SODIUM and aluminium |
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| 2413. |
What is meant by combustion ? Explain it by giving an example. |
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Answer» Solution :Combustion is a REACTION in which a substance is heated in PRESENCE of air or oxygen. During this reaction, carbon present in all allotropic forms undergoes combustion in air to produce carbon dioxide with release of heat and light. `underset("Carbon")(C)+underset("Oxygen")(O_(2))to underset("dioxide")underset("Carbon")(CO_(2))+" Heat and Light"` Almost all carbon compounds also release a large AMOUNT of heat and light on burning. These are one kind of oxidation reactions. For example. `underset("Methane")(CH_(4))+underset("Oxygen")(2O_(2))to underset("dioxide")underset("Carbon")(2CO_(2))+underset("WATER")(2H_(2)O)+" Heat and Light"` `underset("Ethanol")(CH_(3)CH_(2)OH)+underset("Oxygen")(3O_(2))to underset("dioxide")underset("Carbon")(2CO_(2))+underset("Water")(3H_(2)O)+underset("Light")("Heat and")` Saturated hydrocarbons will generally give a clean flame, while unsaturated hydrocarbons give a yellow flame with a release of black SMOKE. |
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| 2414. |
What happens chemically when quick lime is added to water ? |
| Answer» Solution :`underset("QUICK lime")(CAO(s))+H_(2)O(L)tounderset("(Salked lime)")underset("Calcium hydroxide")(Ca(OH)_(2)(aq))+"Heat"` | |
| 2415. |
What are thermochemical reactions ? Give two examples. |
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Answer» Solution :A chemical equation which GIVES the information about the energy changes occurring during the chemical reaction is called a thermochemical equation. `2H_(2)(g)+O_(2)(g)to2H_(2)(l)+571.6kJ`. `N_(2)(g)+3H_(2)(g)to2NH_(3)(g)+92kJ`. |
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| 2416. |
Which of the following is not the criterion of purity of a substance? |
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Answer» solubility |
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| 2417. |
Write one equation for decomposition reactions where energy is supplied in the form of heat, light or electricity. |
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Answer» SOLUTION :`CaCO_(3)(s) overset("Heat") to CAO(s)+CO_(2)(g)` `2AgCl(s) overset("Sunlight") to 2Ag(s)+Cl_(2)(g)` `2H_(2)O(I) overset("ELECTRICITY")to 2H_(2)(g)+O_(2)(g)` |
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| 2418. |
What change do you observe if you test soap with litmus paper? |
| Answer» Solution :The RED litmus turns BLUE as soap is ALKALINE . Blue litmus remains UNAFFECTED. | |
| 2419. |
Write the formula of but-1-ene |
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Answer» Solution :The molecular FORMULA of alkenes is obtained from `C_n H_(2n)`. For but n = 4 . Therefore the molecular formula of butene is `C_4H_8`. In but-1-ene the double BOND is between carbon 1 and 2. so , the sturctural formula of but-1-ene is `CH_3 - CH_2 - CH = CH_2` |
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| 2420. |
What volume of oxygen at N.T.P is needed to cause the complete combustion of 200 mL of acetylene ? Also calculate the volume of carbon dioxide formed. |
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| 2421. |
When an aqeous solution of copper (II) sulphate is electrolysed between two copper electrodes , the blue colour ions are discharged and deposited as metallic copper at cathode . But the blue colour of the solution does not fade . Explain. |
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Answer» Solution :Because as the `Cu^(2+)` ions are reduced at the cathode at the same TIME equal NUMBER of `Cu^(2+)` ions are produced by the oxidation of anodic COPPER . (a) `Cu^(2+) + 2E^(-) to Cu` (b) `Cu to Cu^(2+) +2e^(-)` |
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| 2422. |
Write the structural formulae of the following compounds : (1) Methanoic acid (2) 1-Bromobutane (3) Methanal (4) 2-Bromopropane (5) Butanal (6) Pentene (7) Pentyne (8) Pentan-2-one |
Answer» SOLUTION :
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| 2423. |
Why are the elements of group 17 called halogens? |
| Answer» SOLUTION :Because the elements of GROUP 17 FORM SALTS with the metals of group 1. The name halogen is derived from the Greek HALOGENES, which means salt former. | |
| 2424. |
What is the formula and the electron-dot structure of cyclopentane? |
Answer» SOLUTION :`C_5H_10` 
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| 2426. |
What do n and 2n - 2 signify in the general formula of alkynes? |
| Answer» Solution :In the GENERAL FORMULA of ALKYNES, n represents the number of C atoms and 2N - 2 represents the number of H atoms. | |
| 2427. |
What is covalent bond? What type of bond exists in the following? i] C Cl_4 "" ii] CaCl_2 "" iii] CH_4 "" iv] NH_3. |
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Answer» Solution :Chemical bonds formed between two ATOMS by the sharing of ELECTRONS between the atoms of the same ELEMENT or different ELEMENTS is called covalent BOND. i] `C CI_4` Covalent bond `"" ` ii] `CaCl_2` : ionic bond iii] `CH_4` Covalent bond `""` iv] `NH_3` Covalent bond. |
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| 2428. |
You have two solutions A and B. the pH of solution A is 6 and pH of solution B is 8. (a) Which solutoin is acidic and which is basic ? (b) which solution has more H+ concentraiton ? (c ) Why is HCl a stronger acid than acetic acid ? |
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Answer» SOLUTION :(a) Solution A is acidic. (b) Solution A (C ) As HCl releases more `H^(+)` ions into the solution than acetic acid. It is the CONCENTRATION of hydrogen ion in solution which determines the STRENGTH of the acid. HENCE HCl is a stronger acid than acetic acid. |
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| 2429. |
Which chemical process is used for obtaining a metal from its oxide? |
| Answer» SOLUTION :REDUCTION | |
| 2430. |
What is flux ? Give example. |
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Answer» SOLUTION :It is the substanceadded to the oreto reduce the FUSION TEMPERATUREAND to removethe IMPURITIES . E.g. Calciumoxide ( basic ), Silica ( acidic ). |
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| 2431. |
Which of the following reactions are correct ? |
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Answer» `underset("Propanol")(CH_(3)CH_(2)CH_(2)OH)overset("Alkaline "KMnO_(4))underset(+" Heat")tounderset("Acetic acid")(CH_(3)COOH)` |
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| 2432. |
X g of CO_(2) is prepared by thereaction of CaCO_(3) and HCl. How many grams of oxygen will be liberated, if X grams of CO_(2) completely take part intheprocess of photosynthesis ?144 g of water is produced in the first reaction. Equation for photosynthesis is CO_(2) + H_(2)O to C_(6)H_(12)O_(6)+O_(2) |
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Answer» Solution :`CaCO_(3) + 2HCl to CaCl_(2) + CO_(2) + H_(2)O` `6CO_(2) + 6H_(2)O to C_(6)H_(12)O_(6) + 6O_(2)` Number of moles of WATER formed in thefirst reaction = `(144)/18 = 8` Number of moles of `CO_(2)` produced= 8 Number of moles of oxygen produced by using8 moles `CO_(2)` is 8 . WEIGHT of oxygen liberated ` = 32 xx 8 = 256` g |
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| 2433. |
Which of the statements about the reaction below are incorrect ? 2PbO(s)+C(s)to2Pb(s)+CO_(2)(g) Lead oxide is getting reduced. (i) (a) and (b)(ii) (a) and (c ) (iii) (a), (b) and (c )(iv) All. |
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Answer» SOLUTION :LEAD OXIDE is getting reduced is correct ANSER. As statements (a) and (b) are incorrect, answer (i) is correct. |
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| 2434. |
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity. |
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Answer» SOLUTION :(a) Decomposition by the use of heat : `{:("(i) "2Pb(NO_(3))_(2)(s)overset("Heat")(to)2PbO(s)+4NO_(2)(G)+O_(2)(g)),("(ii)"CaCO_(3)(s)overset("Heat")(to)CaO(s)+CO_(2)(g)):}` (B) Decomposition by the use of LIGHT : `{:("(i) "2AgCl(s)overset("Light")(to)2Ag(s)+Cl_(2)(g)),("(ii) "2AgBr(s)overset("Light")(to)2Ag(s)+Br_(2)(g)):}` (c) Decomposition by the use of electricity : `2H_(2)O(L)overset("Electricity")(to)2H_(2)(g)+O_(2)(g)` |
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| 2436. |
Write the formula to calculate the magnification produced by a spherical mirror. |
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Answer» SOLUTION :m = HEIGHT of the IMAGE / Height of the OBJECT ` m = (H^1)/(h)` |
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| 2437. |
Write three different chemical reactions showing the conversion of ethanoic acid to sodium ethanoate. Write balanced chemical equation in each case. Write the name of the reactants and the products other than ethanoic acid and sodium ethanoate in each case. |
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Answer» Solution :`CH_(3)COOHunderset"Sodium carbomte"(+Na_(2)CO_(3))rightarrow2CH_(3)COONa+UNDERSET"Carbon dioxide" underset(+CO_(2))underset"Water"(H_(2)O)` `CH_(3)COOHunderset"CARBONATE"underset"Sodium hydrogen"(+NaOH)rightarrowCH_(3)COONa+underset"Water"(H_(2)O)` `2CH_(3)COOH+underset"SOdium"(2Na)rightarrowCH_(3)COONa+underset"Hydrogen gas"(H_(2))` |
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| 2438. |
What happens when metal oxide reacts with acid ? |
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| 2439. |
Under what conditions , addition of insert gas affects the equilibriumposition in case of the following equilibrium at constant temperature . Give a reason in support of your answer. (a) decomposition of NO to N_(2) and O_(2) (b) decomposition of SO_(3) (c) formation of CH_(3)OHfrom CO and H_(2) |
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Answer» Solution :`2NO hArrN_(2)+O_(2)` The above equilibirum is associated with no change in VOLUME. Therefore additon of inert gas has NOEFFECT on the EQUILIBRIUM under any condiontion. (b) `2SO_(3)hArr2SO_(2)+O_(2)` The above equilibrium is associated with INCREASE in volume. Addition of an inert gas has no effect has no effect at CONSTANT volume. At constant pressure, addition of inert gas favours the forward reaction since increases in volume takes place. (c) `CO_((g))+2H_(2(g))hArrCH_(3)OH_((g))` The above equilibrium is associated with decreases in volume. Addtion of the inter gas favours back-ward reaction since increases in volume takes place. |
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| 2440. |
What is reproduction? What are its two types? Which one of the two confers new characteristics on the offsprings and how? |
| Answer» SOLUTION :Reproduction is the process of PRODUCING NEW individuals of the same species by existing organisms of a species.i.e, parents. Its two TYPES are , Sexual and Asexual reproduction Sexual reproduction confers new characteristics on the offsprings DUE to variation in DNA. | |
| 2441. |
Write two points of dillerence between electric energy and electric power Out of 60W and 40W lamps which one has higher elecrieal resistance when in use. What is the commerical unit of electric energy? Convert it into joules. |
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Answer» SOLUTION :Electric energy The work done or energy supplied by the source in maintaining the flow of electriç current is called electrical energy. It appears in the from of heat given by `H = VIt = (v^(2)t)/(R)=1^(2)RT` It is cqual to be product of power and time E = P x t It SI unit is JOULE (J) 1J= 1Wx 1S Electric energy The time rate at which electronic energy is consumed or dissptied by an electrical divice is called electric power and is given by `P = VI = (v^(2))/(R) = I^(2)R` It is equal to the rate of doing work by an energy source `P = (W)/(t)` Its SI unit is watt(W) `1W = 1 JS^(-1)` (b) For the same applied voltage `P & (1)/(R)` i,e less the same power of clectrical device higher it is electrical resistance. ( c ) Kilowatt hour - commercial unit of electrical energy. 1 kwh = 1000 wh `= 1000 j//Sxx3600` see `3600000 J - 3.6 xx 10^(6)J` |
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| 2442. |
When lithium metal is placed in hydrochloric acid,………..gas is evolved. |
| Answer» SOLUTION :HYDROGEN | |
| 2444. |
What is water crystallization? |
| Answer» SOLUTION :The number of water molecules found in the crystalline SUBSTANCE is CALLED water of CRYSTALLIZATION. | |
| 2445. |
Which is a neutralisation reaction : |
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Answer» `NaOH + HCL to NACL + H_2O` |
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| 2446. |
Which of the following compounds does not belong to the homologous series ? |
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Answer» `CH_(4)` |
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| 2447. |
Which of the following acid is present in guava? |
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Answer» ACETIC acid |
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| 2448. |
What is the valency of magnesium with atomic number 12 and sulphur with atomic number 16? |
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Answer» Solution :(i) ATOMIC number of magnesium = 12 Electronic configuration is 2, 8, 2. A magnesium atom can lose its 2 valence electrons to achieve the inert gas electronic configuration of neon (2,8). Therefore, VALENCY of magnesium = 2. (ii) The atomic number of sulphur = 16. Electronic configuration = 2, 8, 6. A sulphur atom cannot lose 6 electrons to achieve inert gas electronic configuration due to ENERGY consideration. It can gain 2 electrons to achieve the nearest inert gas electronic configuration of argon (2, 8, 8). Thus, the valency of sulphur = 2. |
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| 2449. |
The term 'pH' comes from |
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Answer» HYDROGEN purity |
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| 2450. |
Write the chemical equations for theEthyne to ethene conversion |
| Answer» SOLUTION :`HC -= CH OVERSET(H_2)(to) H_2C = CH_2` | |