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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.
| 1751. |
When any strong electrolyte is subjected to electrolysis, are equal number of moles of products formed at cathode and anode for the passage of same quantity of electricity?Explain. |
| Answer» Solution :When a strong electrolyte is subjected to electrolysis, it is not necessary that EQUAL number of MOLES of cathodic and anodic products are formed. It depends on the relative charge of CATION and ANION in that electrolyte and the number of electrons involved in the respective cathodic and anodic reactions | |
| 1752. |
Which of the following are correct structural isomers of butane ? |
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Answer» (i) and (III) |
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| 1755. |
Where do you think should hydrogen be placed in the modern periodic table ? |
| Answer» SOLUTION :HYDROGEN should be PLACED in PERIOD 1 | |
| 1756. |
What were the limitations of Döbereiner's classification? |
| Answer» SOLUTION :Döbereiner could identify only three triads from the elements KNOWN at that time. HENCE, this classification of elements was not FOUND to be useful. | |
| 1757. |
What happens when gypsum is heated to 373 K ? Give chemical equations . |
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Answer» Solution :It is PREPARED by HEATING gypsum `(CaSO_4. 2H_2O)` at 373K ina kiln . `underset("Plaster of Paris")(CaSO_4. 2H_2O) to underset(373K)overset("Heat")to underset("Gypsum")(CaSO_4. 1/2 H_2O) + 1""1/2 H_2O ` `underset("Gypsum")(2CaSO_4 . 2H_2O) overset(373K) to underset("Plaster of Paris ")((CaSO_4)_2. H_2O) + 3H_2O ` It may be noted that the temperature should be controlled carefully. It should not be allowed to rise above 425 K, because the whole of water is lost and anhydrous calcium sulphate `(CaSO_4)` is produced. It is called dead burnt plaster. It has no such property as that of Plaster of Paris. When mixed with water, it FORMS a paste which sets into a hard mass. This is called SETTING of Plaster of Paris. The setting of Plaster of Paris is due to its hydration into gypsum. `(CaSO_4)_2. H_2O + 3H_2O to underset("(Gypsum)")(CaSO_4. 2H_2O)` |
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| 1758. |
Which metal is used as the best conductor of heat ? |
| Answer» Solution :Silver and COPPER are BEST CONDUCTORS of HEAT. | |
| 1759. |
Vinegar on dillution with water gives : |
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Answer» ETHANOIC ACID |
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| 1760. |
The total number of elements in period 3 of the periodic table is: |
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Answer» a)2 |
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| 1761. |
What do you observe in activity given in the figure? What are the causes of these observations explain giving reaction ? |
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Answer» Solution :Due to REACTION of SODIUM carbonate with DILUTE hydrochloric acid , CARBON dioxide gas is produced . Lime water tirned milky when `CO_(2)` is passed through it, due to the formation of calcium carbonate. `Na_(2)CO_(3)+2HClrarr2NaCl+CO_(2)` `CA(OH)_(2)+CO_(2)rarrCaCO_(3)+H_(2)O` |
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| 1762. |
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 Ethanoic acid |
Answer» Solution :An atom or a GROUP of atoms/heteroatoms which DETERMINES the chemical PROPERTIES of an ORGANIC compound is called FUNCTIONAL group. 
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| 1763. |
Xenon has an octet configuration in the valence shell but it shows variable valency with the highly electronegative elements like oxygen and fluorine. Comment. |
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Answer» Solution :(i) Xenon belongs to the 5th period (ii) ATOMIC size of xenon in comparison to the other noble gases (iii) comparison of influence of electronegativity of FLUORINE and OXYGEN |
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| 1764. |
Two carbon compounds A and B the molecular formula C_(3)H_(8) and C_(3)H_(6) respectively. Which one of the two is most likely to show addition reaction? Justify your answer. |
| Answer» Solution :Compound A `(C_(3)H_(8))` is saturated and compound B `(C_(3)H_(6))` is unsaturated HYDROCARBON(with a double bond). As we KNOW that addition reactions are a characteristic property of unsaturated hydrocarbons, thus the compound B `(C_(3)H_(6))` is most likely to show addition REACTION. | |
| 1765. |
Write the skeletal equation for the following reactions : Hydrogen sulphide reacts with sulphur dioxide to form sulphur and water. |
| Answer» SOLUTION :`H_(2)S+SO_(2)toS+H_(2)O` | |
| 1767. |
Three alkaline earth metals with electronicconfiguration. |
| Answer» Solution :(i) Beryllium (Be) (2 , 2) (II) Magnesium(MG)(2 , 8,2) (iii) CALCIUM (CA) (2,8,8,2) | |
| 1768. |
Which of the following increase while moving down the group 17 elements ? |
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Answer» ATOMIC RADIUS |
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| 1769. |
Which of the following groups contain only biodegradable items |
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Answer» A) Grass, Flowers and leather |
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| 1770. |
When aluminium is used as a reducing agent , the process is called ____________ process . |
| Answer» SOLUTION :ALUMINOTHERMIC | |
| 1771. |
Write word equations and then balance equations for the reaction taking place when- (a) dilute sulphuric acid reacts with zinc granules. (b) Dilute hydrochloric acid reacts with magnesium ribbon. (c ) dilute sulphuric acidreact with aluminium powder (d) dilute hydrochloric acid reacts with iron fillings. |
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Answer» Solution :`H_2SO_4(aq) to ZN(s) to ZnSO_4(aq) +H_2(G) ` 2HCL(aq) + MG( s) `to ZnSO_4(aq) +H_2( g) ` `3H_2SO_4(aq) +2AL(s) to Al_2(SO_4) _3(aq) +3H_2(g) ` `6HCl(aq) + 2Fe(s) to 2 FeCl_3(aq) +3H_2(g) ` |
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| 1772. |
What is obtained on adding lime to H_(2)O ? |
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Answer» lime |
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| 1773. |
Zinc blende is the sulphide ore of zinc. Can it be concented by electromagnetic separation method ? |
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Answer» |
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| 1774. |
What happens when Ethyl alcohol is treated with potassium dichromate and sulphuric acid. |
| Answer» SOLUTION :`CH_3CH_2OH OVERSET([O])(to)CH_3CHO overset([O])(to) CH_3COOH` | |
| 1775. |
The Sixth period in the periodic table is the longest period and contains 32 elements |
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Answer» |
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| 1776. |
What is a chemical reaction ? |
| Answer» SOLUTION :The PROCESS in which a SUBSTANCE or substances undergo changes to produce new substances with new properties is known as chemical REACTION. | |
| 1777. |
You have two solutions, A and B. The pH of solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of this is acidic and which one is basic ? |
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Answer» Solution :In solution A, `[H^(+) _((aq.))]=10^(-6) M ` In solution B, `[H^(+)_((aq.))]=10^(-8) M ` `:.`Then the solution a has more hydrogen ION concentration . Solution A is acidic `(pH lt 7)` Solution B is basic `(pH gt 7) ` |
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| 1778. |
The weight of an emptychina dish is 39 g andwhen a saturated solution of potassium nitrate is poured into it, its weight is 108g at 50^(@) C. After evaporating the solution to dryness, if theweight of the dish along with the crystals is 72g them thesolubility ofpotassium nitrate at 50^(@) C is _________ . |
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Answer» `83.9` The weight of `KNO_(3)` crystals = 72 - 39 = 33 g The weightof water in saturated solution = 69 - 33 = 36 g `:." Solubility of "KNO_(3) = ("Weight of" KNO_(3))/("Weight of water") xx 100 ` `= 33/36 xx 100 = 91.6" at " 50^(@)C` |
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| 1779. |
What is chemical equation ? |
| Answer» Solution : A chemical EQUATION is a symbolic lic notation that uses formulae instead of WORDS to REPRESENT a chemical equation. | |
| 1780. |
Which of the following reactions is a (are) redox reaction (s) ? |
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Answer» `Ca(OH)_(2) + 2HCI to CaCI_(2) + 2H_(2)O` |
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| 1781. |
Valency of all the alkali metals is |
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Answer» 1 |
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| 1782. |
Translate the following statements into chemical equations and then balance them . (a)Hydrogen gas combines with nitrogen to form ammonia . (b) Hydrogen sulphide gas burns in air to give waterand sulphur dioxide. (c) Barium chloride reacts with aliminium sulphateto give aluminium chloride and a precipitate of barium sulphate. (d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas . |
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Answer» SOLUTION :(a) `3H_(2)+N_(2)rarr2NH_(3)` (B) `2H_(2)S+3O_(2)rarr2H_(2)O+2SO_(2)` (C) `3BaCl_(2)+Al_(2)(SO_(4))_(3)rarr3BaSO_(4)+2AlCl_(3)` (d) `2K+2H_(2)Orarr2KOH+H_(2)` |
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| 1783. |
Which of the above elements have the biggest . · and the smallest atom? |
| Answer» Solution :The element with BIGGEST atom is CAESIUM (Cs) and the element with smallest atom is Lithium (LI). | |
| 1784. |
What is an ore ? |
| Answer» Solution :Ore is a MINERAL from which ONE or more metals can be extracted economically and PROFITABLY. | |
| 1785. |
What is meant by decompostion reaction?Give example. |
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Answer» Solution :A single COMPOUND breaks down to PRODUCE two or more substances.Such type of reaction is called decomposition reaction. `UNDERSET("Copper carbonate (green)")(CuCO_(3))overset(Delta)tounderset("Copper(II)oxide(black)")(CuO+CO_(2)uarr)` |
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| 1786. |
Which one of the following is an example of polyatomic molecule? |
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Answer» SULPHUR |
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| 1788. |
Write the electron dot structural formula and graphic structural formula of ethane |
Answer» SOLUTION :
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| 1789. |
Which of the following statements is correct about an aqueous solution of an acid and a base? (i) higher the pH stronger the acid (ii) Higher the pH, weaker the acid (iii) Lower the pH, stronger the base (iv) Lower the pH, weaker the base |
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Answer» (i) and (iii) |
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| 1790. |
Which one of the following can be used as an acid-base indicator by a visually impared student ? |
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Answer» Litmus |
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| 1791. |
Write the molecular formula of the compounds of the following elements with hydrogen. (C, S, Br, As, F, 0, N, Cl) |
Answer» SOLUTION :
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| 1792. |
What are fossils ? |
| Answer» Solution :The preserved TRACES of the LIVING ORGANISMS are called FOSSILS. | |
| 1793. |
Write the balanced chemical equation for the following reactions. Aluminium + Copper chloride to Aluminium chloride + Copper. |
| Answer» SOLUTION :`2Al+3CuCl_2+K_2SO_4toBaSO_4+2KCl` | |
| 1794. |
What is themeaning of ' Chalcogens? |
| Answer» Solution :All the elementsin group 16 in the periodic tableexcept POLONIUM belong to the chalcogen FAMILY . Chalcogenmeans ' ORE former '. | |
| 1795. |
Two carbon compounds A and B have the molecular formula CH, and C,H, respectively. Which one of the two is most likely to show addition reaction? Justify your answer. Explain with the help of a chemical equation how an addition reaction is useful in the vegetable-ghee industry. |
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Answer» Solution :`C_3H_6`is the unsaturated compound and hence it undergoes addition reaction. `C_3H_6` (propene) undergoes reduction in the presence of NICKEL or PLATINUM catalyst to give a SATURATED hydrocarbon `C_3H_6` (propane). The above reaction finds its application in the INDUSTRY where an unsaturated VEGETABLE oil is converted to its saturated vegetable ghee by carrying out the hydrogenation of oil. 
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| 1796. |
Write the chemical equation of the reaction with an example each in which the following change has taken place: (i) Change in colour (ii) Change in temperature (iii) Formation of precipitate. |
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Answer» SOLUTION :(i) Change in colour : Reaction between lead nitrate solution and potassium iodide solution. `Pb(NO_(3))_(2)(aq)+2KIrarrPbI_(2)(S)+2KNO_(3)(aq)` In this reaction, colour changes from colourles to yellow. (ii) Change in temperature : ACTION of DILUTE sulphuric acid on zinc. `Zn(S)+H_(2)SO_(4)(aq)rarrZnSO_(4)(aq)+H_(2)` In this reaction, heat is evolved (iii) Formation of precipitate : Action of barium CHLORIDE on SODIUM sulphate . `BaCl_(2)(aq)+Na_(2)SO_(4)(aq)rarrBaSO_(4)(S)+2NaCl(aq)(ppt.)` |
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| 1797. |
Write the effect of dilute hydrochloric acid on the colour of the following indicators: Blue litmus |
| Answer» SOLUTION :It will CHANGE RED | |
| 1799. |
Which of the following represents saponification reaction ? |
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Answer» `CH_(3)COONa+NaOH OVERSET(CaO)to CH_(4)+Na_(2)CO_(3)` |
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| 1800. |
Which elements still has dicey position in modern periodic table ? |
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Answer» Carbon |
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