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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.
| 451. |
What is compound ? |
| Answer» SOLUTION :A compound is a pure SUBSTANCE FORMED when TWO or more ELEMENTS combine chemically in a definite ratio by mass. | |
| 452. |
Which two element of the following be longs to the same period ? (Al , Si, Ba, O) |
| Answer» Answer :C | |
| 453. |
Which organic compound is formed when acetic acid is warmed whith ethyl alcohol in the presence of concentrated H_(2)SO_(4) ? |
| Answer» SOLUTION :ETHYL ACETATE . | |
| 454. |
Which elements has two shells, both of which are completely filled with electrons? |
| Answer» SOLUTION :In NEON both the SHELLS are FILLED with ELECTRONS. | |
| 455. |
Which one of the following is the formula of a salt? |
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Answer» HCl |
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| 456. |
What happens when (i) ethanol burns in air. (ii) ethanol reacts with sodium metal. (iii) ethanol is oxidised with chromic anhydride in glacial ethanoic acid. (iv) ethanol is heated with alkaline potassium permanganate. (v) ethanol is heated with ethanoic acid in the presence of a few drops of concentrated sulphuric acid? |
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Answer» Solution :(i) Ethanol is highly inflammable liquid. It catches fire easily and starts burning. Ethanol burns readily in air with a blue flame to form carbon dioxide and water vapour: `C_(2)H_(5)OH+3O_(2) UNDERSET("(Burning)") OVERSET("Combustion")to 2CO_(2)+3H_(2)O` A lot of heat is produced during the combustion of ethanol. (ii) Ethanol reacts with sodium to produce sodium ethoxide and hydrogen gas: `underset("Ethanol")(2C_(2)H_(5)OH)+2Na to underset("Sodium ethoxide")(2C_(2)H_(5)ONa)+H_(2)` (iii) When ethanol is treated with chromic anhydride, then its partial oxidation takes place and ethanal is formed. `underset("Ethanol")(CH_(3)CH_(2)OH) underset(CH_(3)COOH)overset(CrO_(3)" in")to underset("Ethanal")(CH_(3)CHO)` Chromic anhydrideoxidises ethanol to ethanal. (iv) Alkaline `KMnO_(4)` oxidises ethanol to ethanoic acid. `underset("Ethanol")(CH_(3)CH_(2)OH) overset("Alk. "KMnO_(4))to underset("Ethanoic acid")(CH_(3)COOH)` (v) Ethanol reacts with ethanoic acid in presence of concentrated sulphuric acid to form a sweet smelling ester, ethyl ethanoate. `underset("Ethanol")(C_(2)H_(5)OH)+underset("Ethanoic acid")(CH_(3)COOH) overset(H_(2)SO_(4))to underset("Ethyl ethanoate")(CH_(3)COOC_(2)H_(5))+H_(2)O` |
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| 457. |
When do you get a yellow flame? |
| Answer» SOLUTION :When the holes of the bunsen burner are not OPENED, ENOUGH SUPPLY of oxygenrich AIR is not available, hence, incomplete combustion of hydrocarbon produces a yellow flame. | |
| 458. |
Whatis achemicalequilibrium? What areitscharacteristics ? |
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Answer» SOLUTION :ChemicalEquilibrium:Itis stateof a reversiblechemicalreactionin whichno changein theamountof reactantsandproductstakesplace . Atequilibrium, Rateof FORWARDREACTION= Rateofbackwardreaction Characteristicsof equilibrium: (i) IN chemical equilibrium, the ratesof forwardand backwardreactionsare EQUAL . (ii )the observablepropertiessuchas pressure , concentration, colorr, density, viscosityetc., of thesystem reamainunchangedwithtime . (III )Thechemicalequilibriumis a dynamicequilibrium, becauseboththe forwardandbackwardreactionscontinueto occureventhough it appearsstaticexternally. (iv )In physicalequilibrium, thevolumeof ALLTHE phasesremainconstant |
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| 459. |
Which one is a chemical change - fermentation of fruit juice or diluting fruit juice ? |
| Answer» SOLUTION :FERMENTATION of FRUIT JUICE. | |
| 460. |
What is a universal indicator ? |
| Answer» Solution :A universal indicator is a mixture of different organic DYES. It GIVES different COLOURS over a RANGE of pH values. | |
| 461. |
What is meant by atomic size ? Explain the trends in atomic size of elements in aperiod and in a group. |
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Answer» Solution :If an atom is considered to be a sphere, then the term .atomic size. is described by .atomic RADIUS.. Atomic radius : The average distance between the centre of the nucleus and the outermost shell which contains electrons in an isolated atom is called atomic radius. Atomic radius may be expressed in angstroms `(A^(0))` or centimeter (cm) or in picometers (pm). `1A^(0)=10^(-8)cm=10^(-10)m` `1"pm"=10^(-2)m` Variation in atomic radii in a period : On moving from left to right in a period, the atomic number of element increases successively by 1. So nuclear charge increases by 1. Due to this INCREASED nuclear charge, the attraction between electron and nucleus increases, hence the atomic size decreases. Thus, on moving from left to right in a period, there is a trend of decrease in atomic radii.  Variation of atomic radii (atomic size) in a GROUP: On moving dwon a group, a new shell of electrons is ADDED. As a result the distance between the nucleus and the valence shell increases. In a group, the distance between the valence electron and nucleus increases with increase in nuclear charge. Thus, on moving dwon a group, the atomic radii of elements increase gradually.  
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| 462. |
Which compound is used in black and white photography ? |
| Answer» SOLUTION :Silver BROMIDE or silver chloride is USED in black and white PHOTOGRAPHY. | |
| 463. |
Three are three elements X,Y and Z having atomiv numbers of 6,16 and 19 respectively. Based on this information, Rakshit has been asked to answer the following questions: (a) In which group of the periodic table would you expect to find (i) element X (ii) element Y and (iii)( element Z? (b) Which two elements will form ionic bonds ? Why? (c) What will be the formula of ionic compound formed ? (d) Which two elements will form covalent bonds? Why? (e) What will be the formula of covalent compound formed? (f) What values are displayed by Rakshit in answering the above questions? |
Answer» Solution :In order to answer the questions Rakshit first wrote down the electronic CONFIGURATIONS of the element `X,Y` and `Z` by using their atomic numbers as follows:  (a) (i) Element `X` has 4 valence ELECTRONS in its atom, so it will occur in group `4+10=14` of the modern periodic table. (ii)Element `Y` has 6 valence electrons in its atom, so it will be found in group `6+10=16` of the modern periodic table. (iii) Element `Z` has just 1 valence electron in its atom, so it will be in group 1 of the modern periodic table. (b) An IONIC bond is formed between a metal element and a non-metal element. Now, element `Z` of group 1 is a metal and element `Y` of group 16 is a non-metal, therefore, the elements `Z` and `Y` will combine to form ionic bonds (Please note that element `X` of group 14 is ALSO a non-metal carbon but it does not combine with metals to form ionic bonds). (c) The element `Z` has 1 valence electron, so its valencyis 1 (or 1+). Element `Y` has 6 valence electron so its valency will be 2 (or `2-`). Here two `Z^(+)` ions will combine with one `Y^(2-)` ion so that the formula of ionic compound formed will be `Z_(2)Y`. (d) A covalent bond is formed between two non-metal elements. Here, element `X` of group 14 a non-metal and element `Y` of group 16 is also a non-metal therefore, the elements `X` and `Y` will combine together to form covalent bonds. (e) The element `X` has 4 valence electrons, so its valency is 4. The element `Y` has 6 valence electrons so its valency is 2. This means that one atom of element `X` will combined with two atoms of element `Y` to form a covalent compound having he formula `XY_(2)`. (f) The values displayed by Rakshit in answering these questions are (i) Knowledge of modern classification of elements (ii) Understanding of periodic table and chemical bonding and (iii) Problem solving skills. |
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| 464. |
Which one of the following is a general formula for alkene? |
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Answer» `C_(N)-H_(2N)` |
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| 465. |
Which of the following salt solution will turn the blue litmus red? |
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Answer» `KNO_3` |
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| 466. |
Why are the electron affinities of IIA group and IIB group elements less than zero? |
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Answer» SOLUTION :(i) electronic configuration of II A and II B (ii) CHANGE in ENERGY that takes place due to the ADDITION of electron to the neutral ATOM of the elements belonging to the Groups IIA and IIB (iii) relation between change in energy and electron affinity values |
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| 467. |
What are reversible and irreversible reaction? |
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Answer» Solution :Reversible REACTION:A reversible reaction is a reaction that can be reversed ,i.e., the products can be converted BACK to the reactants. e.g., `PCl_(5(g))hArrPCl_(3(g))+Cl_(2(g))` Irreversible reaction:The reaction that cannot be reversed is called irreversible reaction.The irreversible reactions are unidirectional. e.g.,`UNDERSET("Coal")(C_((s)))+underset("Oxygen")(O_(2(g)))tounderset("Carbon dioxide")(CO_(2(g))+Heat` |
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| 468. |
Vinegar is a |
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Answer» STRONG SOLUTION of ACETIC acid |
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| 469. |
Which is used as propeller ? |
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Answer» Stainless STEEL |
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| 471. |
What is called metallic lustre? |
| Answer» SOLUTION :Metals possesses a shining SURFACE in their pure form. This property is CALLED METALLIC lustre. | |
| 472. |
Zn+2HCltoZnCl_(2)+H_(2)uarr The above reaction is an example of… |
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Answer» COMBINATION reaction |
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| 473. |
Which of the following statements is not correct? |
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Answer» a base is a compound which contains EITHER oxide or hydroxide IONS |
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| 474. |
When the gases Sulpherdioxide and Hydrogen sulphide mix in the presence of water, the reaction SO_(2)+2H_(2)S to 2H_(2)O+3S occur. Here hydrogen sulphide is acting as |
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Answer» an OXIDISING agent |
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| 475. |
Which one of the following is not the formula of a salt?HCl NaCl MgCl2 (NH4)2 SO4 |
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Answer» HCl |
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| 476. |
What would be electron dot structure of carbon dioxide which has the formula CO_(2)? |
Answer» SOLUTION :
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| 477. |
You are given a hammer, a battery, a bulb, wires and a switch.(a) How could you use them to distinguish between samples of metals and non metals ? (b) Assess the usefulness of these tests in distinguishing between metals and non-metals. |
| Answer» Solution :(a) Metals can be hammered into thin sheets hence, metal possesses property of malleability while non-metals cannot be beaten into thin sheets. Arrange the BATTERY, bulb, wires and switch in a proper circuit and by passing the electric current, if the bulb glows, then it must be a metal, because metal is a good conductor of electricity. But if the bulb does not glow, then it is a SAMPLE of non-metal, because non-metal is a non-conductor of electricity. (B) FIRST experiment shows that metal possesses property of malleability and ductility, while second experiment justifies that metals are good conductors of electricity while non metals are non-conductor of electricity. | |
| 478. |
Two metals are melted together. The resulting mass is cooled to solidify. The solid is called an alloy. |
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Answer» |
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| 479. |
Which one represents the elements of group 1? |
| Answer» Solution : Li, Na, K | |
| 480. |
Write the reaction in which hydrogen acts as a reducing agent. |
| Answer» SOLUTION :`CUO +H_(2) to Cu+H_(2)O` | |
| 481. |
Write tha name of the following compounds. (a) CH_(3)-Cl (b) CH_(3)-CH_(2)-overset(O)overset(||)(C )-OH (c ) CH_(3)-CH_(2)-CH_(2) - OH (d) CH_(3)-overset(O)overset(||)(C )-H (e) CH_(2)-CH_(2)-Cl (f) CH_(3)-CH_(2)-OH (g) CH_(3)-CH=CH_(2) (h) CH_(3)-CH_(2)-Br (i) CH_(3)-CH_(2)-overset(O)overset(||)(C )-H (j) CH_(3) - C -= CH (k) CH_(3) - OH (l) CH_(3)-overset(O)overset(||)(C )-CH_(3) |
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Answer» Solution :(a) Chloromethane or Methyl Chloride (B) PROPANOIC ACID or Propionic acid (c ) Propanol or Propyl alcohol (d) Ethanal or Acetaldehyde (e) Chloroethane or ETHYL chloride (f) Ethanol or Ethyl alcohol (g) Propene o Propylene (h) Bromoethane or Ethylbromide (i) Propanal or Propionaldehyde (j) Propyne (k) METHANOL or Methyl alcohol (l) Propanone or Acetone. |
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| 482. |
What is the total number of covalent bonds in a molecule of ammonia? |
| Answer» Solution :THREE N - H covalent bond `H-UNDERSET(H)underset(|)OVERSET(* *)N-H` | |
| 483. |
What is the drip-irriagation system used in Meghalaya ? |
| Answer» Solution :The RAINWATER in the hilly areas of Meghalaya is taken DIRECTLY to the fields by using bamboo pipes and allowed to DRIP RIGHT on the PLANTS. | |
| 484. |
The valency of silver in silver carbonate Ag_(2)CO_(3) is |
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Answer» 1 |
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| 485. |
Which of the following is (are) saturated hydrocarbon (s) ? |
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Answer» `CH_(3)-CH= CH-CH_(3)` |
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| 486. |
Which of the following property does not increase across the period? |
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Answer» electronegativity |
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| 487. |
When fats and oils are oxidised, |
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Answer» they become rancid. |
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| 488. |
Three electrolytic cell A, B and C are connected in series that consist of concentrated aqueous solution of sodium chloride (brine solution), fused zinc sulphate and aqueous silver nitrate solution . If 1.4l of chlorine is produced of all gaseous products liberated in B and C at their respective electrodes at STP and the charge required for the deposition. |
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Answer» Solution :`2Cl^(-) rarr Cl_(2) + 2e^(-)` `:.` 11.2 L of chlorine is liberated by passing 96.500 C of electricity 11.2 L of `Cl_(2)` is produced by 96,500 C 1.4 L of `Cl_(2)` is produced by ? `= (1.4 xx 96500)/(11.2) = 12062.5 C` of charge is required ELECTROLYTIC CELL A (aqueous NaCl) `2H^(+) + 2e^(-) rarr H_(2)` `2Cl rarr Cl_(2) + 2e^(-)` Cathodic product is `H_(2)` and ANODIC product is `Cl_(2)` 11.2 1 L of `H_(2)` is produced by 96,500 C? is produced by 12,062.5 C `= (12062.5 xx 11.2)/(96,500) = 1.4 L` Electrolytic cell B (fused `ZnSO_(4)`) Cathode : Zn Anode : `SO_(4)^(2-) rarr SO_(2) + O_(2) + 2e^(-)` `2 xx 96,500 C` gives 22.4 L of `SO_(2)` and 22.4 L of `O_(2)` at STP 12,062.5 C gives ? of `SO_(2)` and of ? of `O_(2)` at SPT `= (12062.5)/(2 xx 96,500) L " of " SO_(2)` and `(22.4 xx 12.62.5)/(2xx 96,500) L " of " O_(2)` `= 1.4 L " of " SO_(2)` and 1.4 L of `O_(2)` `V_(SO_(2)) + V_(O_(2)) = 2.8 L` Electrolytic cell C (Aq. `AgNO_(3)`) Cathode : Ag, Anode: `O_(2)` `4OH^(-) rarr 2H_(2)O + O_(2) + 4e^(-)` `4 xx 96,500 C` gives 22.4 L of `O_(2)` at STP, therefore, 2,062.5 C gives ? at STP `= (12062.5 xx 22.4)/(4xx 96,500) = 0.7 L " of " O_(2)` |
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| 489. |
Write the balanced chemical equation and identify the type of reaction in each case. Ethanol is burnt in air to form carbon dioxide, water, and heat. |
| Answer» SOLUTION :`C_(2)H_(5)OH(L)+3O_(2)(G)to2CO_(2)(g)+3H_(2)O(g)+"heat"` | |
| 490. |
What is meant by precipitation reaction ? Explain it with examples. |
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Answer» Solution :CHEMICAL reaction in which an insoluble PRECIPITATE (solid) formed is known as precipitation reaction. For EXAMPLE, reaction between `Ba^(2)` ions 2- of `BaCl_(2)`, and `SO_(4)^(2-)` ions of `Na_(2)SO_(4)` gives white precipitate of `BaSO_(4)`, which is insoluble in water. `BaCl_(2)(aq)+ Na_(2)SO_(4)(aq) to underset("White precipitate")(BaSO_(4)(s))+2NaCl(aq)` Other example : `AgNO_(3)(aq)+NaCl(aq) to underset("White precipitate") (AgCl(s))+ NaNO_(3)(aq)` |
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| 491. |
Tooth enamel is made up of _______ |
| Answer» SOLUTION :CALCIUM HYDROXYAPATITE. | |
| 492. |
The sum of the number of protons and neutrons of an atom is called Atomic number. |
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Answer» |
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| 493. |
Write the IUPAC name of the compound having formulaoverset(3)CH_3 - underset(CH_3) underset(|) (""^2C )= overset(1)(C )H_2 |
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Answer» Solution :There are 3 C atoms in the continuous chain containing double bound, THEREFORE, the root word is .PROP.. There is a double bond in a chain, therefore, the primary SUFFIX is .ene.. There is methyl radical attached to carbon 2 of the chain, therefore, prefix is 2-methyl. Thus, the IUPAC name of the GIVEN compound is Root word + Root word + Primary suffix 2-Methyl + prop + ene = 2-Methylpropene |
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| 495. |
Which of the following compounds is formed when iron reacts with hydrochloric acid ? |
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Answer» FERROUS chloride |
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| 496. |
The salt obtained by partial neutralisation of sodium hydroxide and sulphuric acid is ______ in nature |
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Answer» |
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| 497. |
Which method will you use to reduce the following ? (i) Oxides of less reactive metals (ii) Oxides of moderately reactive metals (iii) Oxides of highly reactive metals. explain by giving a suitable example. |
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Answer» Solution :(i) `2HgO overset("Heat")rarr 2Hg + O_(2)` `2Cu_(2)O + Cu_(2)S overset("Heat")rarr 6Cu + SO_(2)` (ii) Reduction using carbon `ZnO + C rarr Zn + CO` Sometimes, some highly reactive METALS are used as reducing AGENTS. e.g., `3MnO_(2) + 4Al rarr 3Mn + 2Al_(2)O_(3) + "heat"` or `Fe_(2)O_(3) + 2Al rarr 2Fe + Al_(2)O_(3) + "heat"` (ii) Electrolytic reduction e.g., Na, Mg and Ca are obtained by electrolysis of their molten chlorides. |
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| 498. |
What are the types of elements? |
| Answer» SOLUTION :The THREE TYPES of ELEMENTS are metals, non- metals and metalloids. | |
| 499. |
What are the states of matter other than Solid, Liquid and Gas |
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Answer» BOSE EINSTEIN Condensate |
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| 500. |
What is the atomic number of an element of period 2 and group 17 of the periodic table? |
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Answer» 10 |
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