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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.
| 1851. |
What effect does the concentration of H^(+) (aq) ions have on the nature of the solution ? |
| Answer» SOLUTION :It MAKES it ACIDIC. | |
| 1852. |
Why a candle flame burnns yellow, While a highly oxygenated gas - fuel flame burns blue? |
| Answer» Solution :The most important factor determining colour of the flame is oxygen supply and the extent of FUEL oxygen pre-mixing, which determines the rate of the combustion and thus the tempreture and reaction paths, there by producing DIFFERENT COLOURS. In case of CANDLE , it is an incomplete combustion and the yelloe flame, while a highly oxygenated gas flame burns blue of complete combustion raising a very high temperature. | |
| 1853. |
When sodium ethanoate is heated with soda lime, the main product is _____(methane/ethane) |
| Answer» SOLUTION :METHANE | |
| 1854. |
What is meant by functional group in carbon compounds? Write in tabular form the structural formula and the functional group present in the following compounds: (i) Ethanol(ii) Ethanoic acid |
Answer» SOLUTION :An ATOM or a group of atoms which determine the chemical properties of an organic COMPOUND is called a FUNCTIONAL group. 
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| 1855. |
What is the nature of products formed on burning magnesium ribbon and sulphur powder? Mention their effect on litmus paper. |
| Answer» SOLUTION : Burning of MAGNESIUM ribbon and sulphur FORMS magnesium oxide (MgO) and sulphur dioxide `(SO_2)`respectively. Magnesium oxide TURNS red litmus paper blue, as it is basic in nature while sulphur dioxide turns blue litmus paper red due to its ACIDIC nature. | |
| 1856. |
What is the difference between displacement and double displacement reactions? Write equations for these reactions. |
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Answer» Solution :In a displacement reaction, a more REACTIVE element DISPLACES or removes another element from its compound. For example, zinc being more reactive, displaces copper from its compound. `Zn(s)+CuSO_(4)(aq)rarrZnSO_(4)(aq)+Cu(s)` In case of double displacement REACTIONS, two compounds react by exchanging their ions and form two new compounds. For example, silver NITRATE and sodium chloride exchange their ions, `NO_(3)^(-)andCl^(-)` respectively and form two new compounds in the following reaction. `AgNO_(3)(aq)+NaCl(aq)rarrunderset(("White ppt."))(AgCl(s))+NaNO_(3)(aq)` |
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| 1857. |
What is homologous series. State any two characteristics of homologous series. |
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Answer» SOLUTION :A series of COMPOUNDS in which the same functional group substitutes for hydrogen in a carbon chain is called HOMOLOGOUS series. Characteristics of homologous series : (i) The MOLECULAR formulae of any two successive members of a homologous series differ by `-CH_(2)`. (ii) There is a regular gradation in physical properties of members of a homologous series. |
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| 1858. |
What is meant by double displacement reaction?Give example. |
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Answer» Solution :Double DECOMPOSITION reaction is the reaction in which exchange of ions between two reactants occur leading to the formation of two DIFFERENT products. e.g `underset("Sodium sulphate")(Na_(2)SO_(4))+underset("BARIUM chloride")(BaCl_(2))tounderset("(White PRECIPITATE)")underset("Barium sulphate")(BaSO_(4)DARR)+underset("Sodium chloride")(2NaCl)` |
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| 1859. |
What is the pH of 1.0xx10^(-5) molar solution of KOH? |
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Answer» Solution :`KOHtoK^(+)+OH^(-)` `1XX10^(-5)` MOLAR `1xx10^(-5)mol` `[OH^(-)]=1xx10^(-5)implies[H^(+)]=10^(-9)` PH=`-log[H^(+)]` =-log `[10^(-9)]=9` |
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| 1860. |
What are concentrated and dilute solutions. |
| Answer» Solution :Two solutions having same solute and SOLVENT, the one which contains HIGHER AMOUNT of solute PER the given amount of solvent is SAID to be concentrated solution and the another is said to be dilute solution. | |
| 1861. |
What is meant by · periodi city? |
| Answer» SOLUTION :The REPETITION of same propertis after CERTAIN intercal is CALLED PERIODICITY. | |
| 1862. |
Though zinc and manganese get precipitated as their sulphides, they do not get precipitated along with lead or copper when H_(2)S is passed through acidified solution of their salts. Justify and also explain how the precipitation of Zn^(+2) and Mz^(+2) ions takes place |
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Answer» Solution :(i) requisite for PRECIPITATION of the respective sulphides (ii) difference in the TYPES of IONS present in an acidified salt solution and normal salt solution (iii) ions present in the solution when `H_(2)S` is passed through it (iv) influence of EXTRA ions present in the acidified solution on the degree of dissociation of `H_(2)S` (v) relation between the degree of dissociation of `H_(2)S` and the availability of sulphide ions in the solution (vi) relation between the number of sulphide ions and the precipitation of the selective salts |
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| 1863. |
When a fully blown balloon is subjected to sudden bursting. What do you observe? Justifyyour observation. |
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Answer» SOLUTION :(i) SUDDEN expansion of the gas present INSIDE theballoon (ii) change in energy of thesystem due to thesudden expansion of the gas (iii) effect of THECHANGE in energy on temperature (iv) effect of this change in temperature on the surrounding (v) phase transition of a vapour present in thesurrounding |
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| 1864. |
What are the two properties of carbon which enables carbon to form a large number of compounds ? |
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Answer» Solution :Carbon atom forms covalent bonds by sharing of electrons with other atoms to FORM numerous compounds. The number of carbon compounds KNOWN to chemists was RECENTLY estimated about three millions. Carbon has ability to form a large number of compounds. Two factors noticed in this case are as follows: Catenation PROPERTY of carbon : Carbon has the unique ability to form bonds with other atoms of carbon, giving rise to large number of molecules. This property of carbon is called catenation. Carbon compounds consist of long chains of carbon, branched chains of carbon or in the ring form or cyclic form.  Carbon atom may be linked with other atoms by single, double or triple bonds. Compounds of carbon, which are linked by only single bonds between the carbon atoms are called saturated compounds. Compounds of carbon, having double or triple bonds between the carbon atoms are called unsaturated compounds. No other element exhibits the property of catenation to the extent seen in carbon compounds. Silicon forms compounds with hydrogen which have chains of upto seven or eight atoms, but these compounds are very reactive. The carbon-carbon bond is very strong and hence it is stable. Since carbon has a valency of four, it is capable of bonding with four other atoms of carbon or atoms of some other monovalent elements. Compounds of carbon are formed with oxygen, hydrogen, nitrogen, sulphur, chlorine and MANY other elements giving rise to compounds with specific properties which depend on the elements other than carbon present in the molecule. The bond formed by carbon with most other elements are very strong, which makes compounds exceptionally stable. Carbon being small in size, it enables the nucleus to hold on to the shared pairs of electrons strongly. Hence, strong bonds are formed by carbon. |
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| 1865. |
Write the electron dot structures of sodium, oxygen and magnesium. |
Answer» SOLUTION :
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| 1866. |
What is water of crystallisation ? Write the common name and chemical formula of a commercially important compound which has ten water molecules as water crystallisation. How is this compound obtained ? Write the chemical equation also. List any two uses of this compound. |
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Answer» SOLUTION :Water of crystallisation is the fixed number of water molecules present in one formula unit of the compound. The compound having ten water molecules as water of crystallisation in `Na_2CO_3.10H_2O` Its name is washing soda. Washing soda is obtained by heating BAKING soda and recrystallising the sodium carbonate obtained. `2NaHCO_(3) overset("Heat") rarr Na_2CO_3 + H_2O + CO_2` `Na_2CO_3 + 10 H_2O rarr Na_2CO_310 H_2O` Uses of wahing soda : (i) It is used in removing permanent hardness of water. (II) It is used in the manufacture of GLASS, soap and paper. |
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| 1867. |
When an aqueous solution of zinc sulphate is subjected to electrolysis, 280 mL of oxygen gas at STP is liberated at anode. Calculate the quantity of electricity passed through the electrolyte |
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Answer» 0.05 F `0.28 L O_(2)` at STP require `= (4 XX 0.28)/(22.4) = 0.05F` |
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| 1868. |
Which of the following are found in elementary state in nature? |
| Answer» Solution :Noble gases | |
| 1869. |
Which one is the fundamental property of an element-atomic number or mass number? |
| Answer» SOLUTION : ATOMIC NUMBER | |
| 1870. |
What were the criteria used by Mendeléey in creating his Periodic Table? |
| Answer» SOLUTION :ATOMIC MASS | |
| 1871. |
What the size of solute particle in a true solution ? |
| Answer» Solution :The SIZE of such a PARTICLE is LESS than ` 10^(-7)`CM in diameter. | |
| 1872. |
Which is not the limitation of Mendeleev's classification ? Mendeleev's Table |
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Answer» does not satisfactorily explain the position of hydrogen. |
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| 1873. |
Which of the following reactions is not possible? |
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Answer» `ZN(s) + CuSO_4(AQ) to ZnSO_4(aq) + CU(s)` |
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| 1874. |
Write the name and molecular formula of the fourth member of alkane series. |
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Answer» |
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| 1875. |
Write the balanced chemical equtions for the following reactions and identify the type of reaction in each case. (i) Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773 to form ammonia gas. (ii) Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water. (iii) Ethanol is warmed with ethanoic to form ethyl acetate in the presence of concentrated H_(2)SO_(4). (iv) Ethene is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light. |
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Answer» Solution :(i) `N_(2)(G)+3H_(2)(g)underset("773K")overset("Catalyst")rarr2NH_(3)(g)` Combinationreaction (ii) `NaOH(aq)+CH_(3)COOH(aq)rarrCH_(3)COONa(aq)+H_(2)O(l)` Double displacement REACTION/Neutralisation reaction (iii) `C_(2)H_(5)OH(l)+CH_(3)COOH(l)overset(H^(+))rarrCH_(3)COOC_(2)H_(5)(l)+H_(2)O(l)` Double displacement reaction/Esterification reaction (IV) `C_(2)H_(4)(g)+3O_(2)(g)rarr2CO_(2)(g)+2H_(2)O(g)+"Heat"+"Light"` Redox reaction/Combustion reaction |
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| 1876. |
Which of the followingis formed when soap water actson clothes to remove dirt or grease ? |
| Answer» Answer :B | |
| 1877. |
what type of reaction takes place when calcium oxide is reacted with water ? |
| Answer» SOLUTION :COMBINATION REACTION . | |
| 1878. |
What is the chemical formula for Plaster of Paris ? How is it prepared ? State the common and the chemical names of the compound formed when Plaster of Paris is mixed with water. |
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Answer» Solution :`CaSO_4. 1/2 H_2O ` PLASTER of Paris is prepared by heating gypsum to a TEMPERATURE of 393 K . `UNDERSET("Gypsum")(CaSO_4. 2H_2O) overset(393K)to underset("Calcium SULPHATE hemihydrate")(CaSO_4. 1/2 H_2O + 3/2 H_2O)`. |
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| 1879. |
Which of the following can form more than one acid salt? |
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Answer» `CH_(3)COOH` |
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| 1880. |
which of the following compounds contain (s) -CHO as the functional group ? |
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Answer» propanal |
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| 1881. |
Thestateat whichthe rateof forwardreactionbecomesequalto therateof backwardreactionis called________state . |
| Answer» SOLUTION :EQUILIBRIUM | |
| 1882. |
What will be the formula and electron dot structure of cyclopentane? |
Answer» SOLUTION :Formula of CYCLOPENTANE is `C_(5)H_(10)`. The ELECTRON dot structure of cyclopentane is : 
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| 1883. |
Use Mendeléer's Periodic Table to predict the formulae for the oxides of the following elements: K, C, AI, SI, and Ba. |
| Answer» SOLUTION :`K_2O, CO_2, AI_2O_3, SIO_2 and BAO. ` | |
| 1885. |
Whatareisotopes ? |
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Answer» SOLUTION :Isotopesare theatomsof sameelements withsameatomicnumberbutdifferentmassnumber . `e .G(""_(17 )CL ^(35 ),""_(17 )Cl^(37 ))` |
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| 1886. |
What is the meaning of "Repurpose" with respect to conservation of environment? |
| Answer» Solution :REPURPOSE is the PROCESS by which an object with ONE use value is TRANSFORMED or redeployed as an object with an alternative use value | |
| 1887. |
What is a balanced chemical equation ? |
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Answer» SOLUTION :A balanced CHEMICAL equations is one that contains an EQUAL of atoms of each elemetn on both sides of the equation . The following equation is an EXAMPLES. `N_(2)+3H_(2) to 2NH_(3)` |
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| 1888. |
Veena and Seema were coming home after attending the birthday party of their classmateBeena. Beena's mother had prepared a large number of delicious dishes for this occasion. A lot of soft drinks like Coca Cola and Pepsi, etc. were also served. The homemade cake and ice-cream were also there in plenty for everyone. Veena and Seema ate a lot of food, cake and ice-cream. They also had many soft drinks each. Acutally, Seema liked the fool too muchso she ate too much. On reaching home, Seema started feeling uncomfortable. SHe also got pain in the stomach.Seema is a student of class X and her mother Mrs. Sarla is a teacher in the same shcool who teaches science to class X. Mrs. Sarla told her daughter Seema that she had three substance A,B and C in the kitchen which can be consumeds safely. The substances A,B and C give blue colour, orange colour and green colour respectivley with the universal indicator. Mrs. Sarla asked Seema whihc sxubstance would she like to take in order to obtain relief from pain and why? Seema made the right choice and explained the reason to her mother. (a) What is the general, name of the condition which is faced by Seema? (b) Which substance is produced in excess in the stomach that causes the above condition? (c) What is the general name of substances which are usually taken to obtain relief from the above condition? (d) What is the nature of (i) substance A (ii) substance B, and (iii) substance C? (e) Which substance A, B or C do you think was chosen by Seema to get relief from stomach pain? Why? (f) What values are displayed by Seema in this incident? |
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Answer» Solution :(a) Indigestion (b) The excess of HYDROCHLORIC acid is produced in the stomach (due to OVEREATING). (C) The Antacids (which are mild bases haivng no toxic effects on the body). (d) (i) Substance A which gives blue colour with universal indicator is a base (or basic in nature) (ii) Substance B which gies orange colour with universal indicator is an acid (or acidic in nature). (iii) Substance C which gives green colour with universal indicator is neither a base nor an acid, it is neutal in nature. (e) Seema chose substance A which is a base. This is because being basic, the substance A will neutralise excess acid in stomach and give relief from pain and discomfort. (f) The values displayed by Seema are (i) Awareness (or knowledge ) that indigestion caused by over eating is due to the FORMATION of excess hydrochloric acid in the stomach and can be cured by taking antacids (ii) Understanding of the effect of acid and bases on universal indicator, and (iii) Greedy nature (which led to over-eating). |
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| 1889. |
Which of the statements about the reaction below are incorrect? 2PbO(s) + C(s) rarr 2Pb(s) + CO_(2)(g) (a) Lead is getting reduced. (b) Carbon dioxide is getting oxidised. (c) Carbon is getting oxidised.(d) Lead oxide is getting reduced. |
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Answer» (a) and (b) (a) LEAD is GETTING REDUCED and (b) Carbon dioxide is getting oxidised. |
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| 1890. |
Which of the following compounds is used as drying agent ? |
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Answer» CALCIUM oxide |
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| 1891. |
Which of the following during hydrolysis gives an acidic solution in water ? |
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Answer» `KNO_(3)` |
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| 1892. |
Which of the following is not a noble gas? |
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Answer» helium |
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| 1893. |
X is a reddish - brown metal used in electrical wires. When the same metal in powdered form is heated strongly, it turns black. When hydrogen gas is passed over this black substance it regains its original colour. The metal X is |
| Answer» ANSWER :C | |
| 1894. |
w/V% can be written in which of the following manner? |
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Answer» `(w)/(w)% xx "density"` |
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| 1895. |
Two compounds 'A' and 'B' have the molecular formula C_(3)H_(8) and C_(3)H_(6) respectively. Which one of the two is most likely to show addition reactions? Justify your answer. Explain with the help of a chemical equation, how an addition reaction is useful in vegetable ghee industry. |
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Answer» SOLUTION :A. is SATURATED hydrocarbon PROPANE. <BR. .B. is unsaturated hydrocarbon `CH_(2) = CH -CH_(3)` which will undergo addition reaction. e.g. `CH_(3)=CH-CH_(3)+Br_(2)rightarrowunderset"(1,2 -dibromo-propane)"(CH_(2)Br-CHBr-CH_(3))` `"VEGETABLE oil"+H_(2) rightarrow"Vegetable ghee"` 
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| 1896. |
Whatis calleduniversalpHindicator ? |
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Answer» Solution :UniversalIndicator /pHpaper : (i)It ismixtureof a NUMBER of INDICATORS . (II)it shows a specificcolourat a givenpH . |
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| 1897. |
Which metal does not react with either cold or hot water but reacts with steam? |
| Answer» SOLUTION : Aluminium, iron and ZINC do not react with COLD and hot water, but they react with steam. | |
| 1898. |
What are biodegradable and non-biodegradable detergents? |
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Answer» Solution :BIODEGRADABLE detergents: They have straight hydrocarbon CHAINS, which can be easily degraded by BACTERIA. Non-biodegradable detergents: They have HIGHLY BRANCHED hydrocarbon chains, which cannot be degraded by bacteria. |
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| 1899. |
Unsaturated hydrocarbons contain multiple bonds between the two carbon atoms and show addition reactions. Give the test to distinguish ethane from ethene. |
| Answer» SOLUTION :When unsaturated hydrocarbons are treated with acidified potassium PERMANGANATE, they decolourise the solution, the pink colour of the solution DISAPPEARS and becomes colourless. When ethene is MIXED with acidified potassium permanganate solution it decolourises the solution whereas ethane, if treated with the same solution, doesn.t SHOW any colour change. | |
| 1900. |
Why acetic acid is known as glacial acetic acid? |
| Answer» SOLUTION :Because it freezes during WINTER or under cold CLIMATE CONDITION. | |