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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.
| 1. |
`2HOCl to2HCl+O_(2)` is a ____________ decomposition reaction. |
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Answer» Correct Answer - photolytic photolytic `2HOCl to2HCl+O_(2)` is photolytic decomposition reaction. |
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| 2. |
Formation of clouds , mist and fog are the examples of ____________.A. chemical combination of `O_(2)and H_(2)O`.B. physical change which involves condensation of water vapourC. physical change which involves sublimation.D. chemical change which involves absorption of huge amounts of energy. |
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Answer» Correct Answer - 2 Formation of clouds , mist etc ., are the examples of physical changes. |
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| 3. |
Magnesium attains octet configuration by ____________ electrons. |
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Answer» Correct Answer - losing two losing two Electronic arrangement of Mg is 2 , 8 , 2 . By losing two electrons , it attains octet configuration. |
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| 4. |
Which among the following reactions is not balanced ?A. `2KClO_(3) to2KCl+3O_(2)`B. `2Fe(OH)_(3)+4H_(2)SO_(4)toFe_(2)(SO_(4))_(3)+6H_(2)O`C. `2Pb(NO_(3))_(2)to2PbO+4NO_(2)+O_(2)`D. `2KNO_(3)+FeSO_(4)toFeSO_(4)toK_(2)SO_(4)+Fe(NO_(3))_(2)` |
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Answer» Correct Answer - 2 Second reaction is wrongly balanced . Correct balancing is as follows. `2Fe(OH)_(3)+3H_(2)SO_(4)toFe_(2)(SO_(4))_(3)+6H_(2)O` |
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| 5. |
Which of the following is a physical change ?A. Dissolution of lime in water.B. Dissolution of `CO_(2)` in water at high pressure.C. Dissolution of concentrated acid in water.D. Electrolysis of water. |
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Answer» Correct Answer - 3 Dissolution of any acid to water makes acid dilute . Hence it involves only a physical change. |
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| 6. |
Which among the following is not a characteristic of a physical change?A. The change is temporary.B. No new substance is formed.C. Molecular formula of a compound changes.D. Change of state of matter takes place without any change in molecular composition. |
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Answer» Correct Answer - 3 In physical change , molecular composition that is molecular formula remains the same. |
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| 7. |
Which of the following involves only physical change ?A. Dissolution of lime in water.B. Dissolution of carbon dioxide in water at high pressure.C. Dissolution of concentrated acid in water.D. Electrolysis of water. |
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Answer» Correct Answer - 3 Dissolution of any acid in water makes acid dilute. Hence it involves only a physical change. |
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| 8. |
If the formula of respective chlorides of X and Y are `XCl_(3) and Ycl_(4)` respectively , then the valencies of X and Y areA. 3 and 2B. 3 and 4C. 1 and 1D. 1 and 4 |
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Answer» Correct Answer - 2 `XCl_(3),YCl_(40) to` the valency of X and Y are 3 and 4. |
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| 9. |
`CuSO_(4)+XtoXSO_(4)+Cu,CuSO_(4)+YtoYSO_(4)+Cu,` `XSO_(4)+YtoNo` reaction , `CuSO_(4)+ZtoNo` reaction, Arrange Cu , X, Y and Z in the ascending order of reactivity.A. X, Y, Z, CuB. Cu , Y , X , ZC. Cu , X, Z, YD. Z , Cu , Y , X |
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Answer» Correct Answer - 4 `CuSO_(4)+XtoXSO_(4)+Cu` `:.X` is more reactive than Cu `CuSO_(4)+YtoYSO_(4)+Cu` `:. Y` is more reactive than Cu `XSO_(4)+Yto` No reaction `:.X` is more reactive than Y `CuSO_(4)+Zto` No reaction `:.Z` is less reactive than Cu `:.` order is `ZltCu ltYltX` |
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| 10. |
Arrange the following sequence in order to derive the formula of zine oxide. (a) The valencies of ions formed by zine and oxygen are written below without positive and negative sign. (b) The positive ion that is `Zn^(+2)` followed by the negative ion , that is oxide `(O^(-2)` ion are written with ther charges. (c ) The valencies of zinc and oxide ion have common factors and hence they are divided by their highest common factor. (d) The magnitude of valencies of the ions should be interchanged and written as subscripts on right side of the respective ions.A. badcB. abcdC. bacdD. cabd |
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Answer» Correct Answer - 3 (i) The posiitive ion that is `Zn^(+2)` followed by the negative ion that is `O^(-2)` are written with their charges. (ii) The valencies of ions formed by zine and oxygen and are written below without positive and negative sign. (iii) The valencies of zinc and oixde have common factors and hence they are divided by the highest common factor. (iv) The magnitude of the valencies of the ions should be interchanged and written as subscripts on right side of the respective ions. |
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| 11. |
Arrange the points in sequence to draw the geometrical representation of an atom which is resprecented as `_(Z)X^(A)`. (a) Calculation of the number of protons and neutrons. (b) Identification of the atomic number and mass number of the given element. ( c) Placement of the electrons in shells around the nucleus according to the electronic configuration. (d) Wirting the electronc configuration of the atom. (e) Protons and neutrons are shown in nuleus.A. baedcB. bacdeC. abcdeD. ecbad |
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Answer» Correct Answer - 1 (i) Identification of the atomic number and the mass number of the given element. (ii) Calculation of the number of protons and neutrons. Protons and neutrons are show in nucleus. (iii) Protons and neutrons are show in nucleus. (iv) Placement of the electrons in shells around the nucleus according to the electronic configuration. |
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| 12. |
Four types of reactions are given below in a particular order. (1) Displacement reaction (2) Combination reaction (3) Double displacement displacement (4) Decomposition reaction Following this sequence to arrange the reaction given below. (a) `A+BtoAB`. (b) `ABtoA+B` ( c) `AB+CtoCB+A` (d) `AC+BDtoAD+BC`A. cadbB. bacdeC. bdacD. acbd |
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Answer» Correct Answer - 1 (i) `AB+CtoCB+A` (ii) `A+BtoAB` (iii) `AC+BDtoAD+BC` (iv) `ABtoA+B` |
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| 13. |
(a) `H_(2)+Br_(2)to2HBr` (b) `HBr+NaOHtoNaBr+H_(2)O` (c ) `2NaBr+Cl_(2) to2NaCl+Br_(2)` (d) `2NaCl to2Na+Cl_(2)` Arrange the above reactions in order s double displacement reaction, combination reaction, decomposition reaction and displacement reaction.A. badcB. bdacC. bacdD. abdc |
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Answer» Correct Answer - 1 (i) `HBr+NaOHtoNaBr+H_(2)O` (ii) `H_(2)+Br_(2)to2HBr` (iii) `2NaCl to2Na+Cl_(2)` (iv) `2NaBr+Cl_(2)to2NaCl+Br_(2)` |
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| 14. |
Among the following reactions , identify the synthesis reaction.A. `2SO_(2)+O_(2)to2SO_(3)`B. `C+O_(2)toCO_(2)`C. `CaO+H_(2)OtoCa(OH)_(2)`D. `2H_(2)Oto2H_(2)+O_(2)` |
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Answer» Correct Answer - 2 `C+O_(2)toCO_(2)` is an example of synthesis reaction. |
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| 15. |
The formula of chloride of a metal is `MCl_(2)` . What is the valency of the metal?A. 4B. 3C. 1D. 2 |
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Answer» Correct Answer - 4 Since the valency of chlorine is 1 , the valency of metal `MCl_(2)` is 2. |
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| 16. |
Match the element in column A with the valency exhibited by the element given in column B `{:(,"Column A",,,"Column B"),((A),"Neon",(),(a)," "4),((B),"Oxygen",(),(b)," "3),((C),"Potassium",(),(c)," "2),((D),"Boron",(),(d)," "1),((E),"Silicon",(),(d)," "0):}`A. `Atob," " Btoc," " Ctod, " " Dtoe, " " Etoa`B. `Atob," " Btoc," " Ctoa, " " Dtoe, " " Etod`C. `Atoe," " Btod," " Ctoa, " " Dtob, " " Etoc`D. `Atoe," " Btoc," " Ctod, " " Dtob, " " Etoa` |
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Answer» Correct Answer - 4 `Atoe` Atomic number of neon is 10 and electronic configuration 2 , 8 valency is zero. `Btoc` Atomic number of oxygen is 8 and electronic configuration 2 , 6 valency = 8 - 6 = 2 `Cto d` Atomic number of potassium is 19 and electronic configuration is 2 , 8 , 8 , valency = 1 `Etoa` Atomic number of silicon is 14 and electronic cofiguration is 2 , 8 , 4 valency = 4 |
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| 17. |
Assertion (A) : sodium formss a monovalent ion. Reason (R ) : Sodium loses only one electron from second last shell.A. Both A and R are true and R is the correct explanation For A.B. Both A and R are true but R is not the correct explanation for A.C. A is true and R is false.D. A is false and R is true. |
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Answer» Correct Answer - 3 Sodium loses only one electron from its outer most shell or valence shell and forms monovalent ion. |
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| 18. |
Which of the following is a chemical change ?A. Formation of cloudsB. Formation of rustC. Manufacture of milk powder from milkD. Formation of black coating on the walls of tube light |
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Answer» Correct Answer - 2 Formation of rust is a chemical change in which iron when exposed to humid atmosphere forms hydrated ferric oxide . `(Fe_(2)O_(3).xH_(2)O)` |
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| 19. |
The number of neutrons are equal to the number of protons present in the nucleus of two elements X and Y and their dinegative ions possess 8 electrons in L and M shells respectively . Then the ratio of mass number of the two elements isA. `1 : 2`B. ` 2 : 3`C. `3 : 4`D. ` 2 : 5` |
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Answer» Correct Answer - 1 The electronic configuration of the dinegative ion with 8 in electrons in L valence shell is : `X^(-2)to2,8` `Xto2,6 `( Z) , mass number is 16 for X. The electronic configuration of the dinegative ion with 8 electrons is M shell is `Y^(-2)to2,8,8` `Yto2,8,6 (Z)` Mass number is 32 (A) for Y. Ratio of mass number is `16 :32rArr1 :2` |
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| 20. |
`2KMnO_(4)+H_(2)C_(2)O_(4)toK_(2)SO_(4)+2MnSO_(4)+10CO_(2)+8H_(2)O`. ltvrgt Potassium permanganate oxidises oxalic acid in acidic medium as per the above chemical reaction. Identify the coefficient of `H_(2)SO_(4)` in the above equatio.A. 3B. 4C. 5D. 2 |
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Answer» Correct Answer - 1 `2KMnO_(4)+3H_(2)SO_(4)+5H_(2)C_(2)O_(4)toK_(2)SO_(4)+2MnSO_(4)+10CO_(2)+8H_(2)O`. |
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| 21. |
Identify the atomic number of the element which possess same number of electrons in L and M shells.A. 18B. 19C. 16D. 18 |
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Answer» Correct Answer - 2 `{:("Atomic number (Z) ","Electronic configuration"),(" "19," "2_(,)8_(,)8_(,)1),(" "20," "2_(,)8_(,)8_(,)2):}` |
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| 22. |
Identify the number of neutrons present in a pair of element with atomic numbers 20 and 13 , if their mass numbers are 40 and 27 respectively.A. 20 and 13B. 20 and 20C. 17 and 20D. 20 and 14 |
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Answer» Correct Answer - 4 A- Z = number of neutrons. (1) 40 - 20 = 20 (2) 27 - 13 = 14 |
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| 23. |
Melting of wax is a ________.A. chemical changeB. decomposition reactionC. both physical and chemical changeD. physical change |
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Answer» Correct Answer - 4 Melting of wax is a physical change |
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| 24. |
The reaction `AgNO_(3)+NaCl toAgCl+ NaNO_(3)` is a ________ reaction.A. chemical displacementB. chemical combinationC. double displacementD. decomposition |
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Answer» Correct Answer - 3C. double displacement `AgNO_(3)+NaCl toAgCl+ NaNO_(3)` is a double displacement reaction. |
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| 25. |
Which of the following elements is chemically inactive ?A. NitrogenB. NeonC. HydrogenD. Copper |
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Answer» Correct Answer - 2 Insert geses like He , Ne , Ar are chemically inactive. |
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| 26. |
Identify the ratio of the coefficients of the products `CuO,NO_(2) and H_(2)O` formed respectively when hydrated copper nitrate is thermally decomposed. `Cu(NO_(3))_(2).6H_(2)OtoNO_(2)+H_(2)O+O_(2)`A. `2 : 3 : 1`B. `1 : 2 : 3`C. `1 : 1.5 : 1`D. `3 : 2 : 1` |
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Answer» Correct Answer - 2 `2Cu(NO_(3))_(2).6H_(2)Oto2CuO+4NO_(2)+O_(2)+6H_(2)O` Coefficients of CuO, `NO_(2) and H_(2)O` are respectively 2 , 4 and 6. `:.` Ratio is `1 : 2 : 3` |
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| 27. |
Identify the number of neutrons present in a pair of elements with atomic numbers 20 and 13 if their mass numbers are 40 and 27 respectively.A. 20 and 13B. 20 and 13C. 17 and 20D. 20 and 14 |
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Answer» Correct Answer - 4 `A-Z=n` (1) 40 - 20 =20 (2) 27 - 13 =14 |
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| 28. |
If a uninegative ion has 10 neutrons and 9 protons , electronic configuration of the atom of the element isA. 2, 8, 1B. 2, 7C. 2, 8D. 2, 8 , 8 |
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Answer» Correct Answer - 2 `X^(-) = 9` protons (Z) 10 neutrons 10 electrons `Xoverset(+1e^(-))toX^(-1)` (9 electrons) " " (10 electrons) Therefore , the electronic configuration of an atom is 2 , 7 |
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