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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.
| 6202. |
Enthalpies of formation of CO(g), CO_(2)(g), N_(2)O(g) and N_(2)O_(4) " are " -110, -393, 81 and 9.7 kJ mol-1 respectively. Find the value of Delta_(r ) H for the reaction , N_(2)O_(4) (g) + 3 CO(g) rarr N_(2)O (g) + 3CO_(2) (g) |
| Answer» SOLUTION :`-777.7 KJ MOL^(-1)` | |
| 6203. |
Enlist the common properties of metals. |
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Answer» SOLUTION : The common PROPERTIES of metals are as follows: (1) Metals possess shining on their surface (LUSTRE) in their pure form. (2) Metals are solid and hard. (3) Metals possess properties of malleability and ductility. (4) Metals are good conductors of heat and electricity. (5) Metals have HIGH melting points and boiling points. (6) Metals are sonorous. |
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| 6204. |
Energy transfer is said to be unidirectional where biochemical transfer is said to be cyclic? Why. |
| Answer» Solution :The FLOW of energy is unidirectional because the energy LOST as heat to the environment can.t be reutilized by plants for photosynthesis. Energy DECREASE at each tropic level (10% of previous level). Hence it can.t be reused again. Whereas biochemical transfer is CYCLIC because nutrients utilized by plants and animals are returned to environment after the death of organisms. | |
| 6205. |
Energy of resonance hybrid is less as compared to the contributing canonical structures. |
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| 6206. |
Energy of an electron increases with increase in distance from the nucleus. Comment on the change in kinetic energy and potential energy. |
| Answer» SOLUTION :factors affecting kinetic energy and POTENTIAL energy of an ELECTRON. | |
| 6207. |
Energy of an electron in a particular orbit of single electron species of beryllium is the same as the energy of an electron in the ground state of hydrogen atom . Identify the orbit of beryllium |
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Answer» 1 Energy of the electron in ground state hydrogen atom = -13.6 EV `THEREFORE(-13.6)/(n^2)xx4^2=-13.6` `rArrn^2=42` `n=42` |
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| 6208. |
Energyis released: Combination reaction::energyis absorbed :________. |
| Answer» SOLUTION :DECOMPOSITIONREACTION | |
| 6209. |
Endoscope is made up of |
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Answer» GLASS wool |
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| 6210. |
Empirical formula of a compound is CH_2O.Its molecular mass is 60. The molecular formula will be |
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Answer» `CH_2O` Empirical formula mass ` = 1 xx 12 + 2 xx 1 + 16 = 30` MOLECULAR mass = 60 n FACTOR = molecular mass/empirical formula mass ` = 60/30=2 ` molecular formula ` = (EF)_2` ` = (CH_2O)_2` ` = C_2H_4O_2` |
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| 6211. |
Empirical formula of a compound is A_(2)B_(4). If its empirical formula weight is half of its vapour density, determine themolecular formula of the compound. |
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Answer» `A_(4)B_(8)` Molecular formula weight = 2X `n=("Molecular formula weight")/("Empirical formula weight ")=(2x)/(x/2) = 4` Molecular formula = `4 xx A_(2)B_(4) = A_(8)B_(16)` |
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| 6212. |
Select the whether the statement is true or false.Empirical formula =" (Molecular formula)"_(n). |
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| 6213. |
Empirical formula, (ii) molar mass of the gas, and (iii) Molecular formula. |
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| 6214. |
Emf of a voltaic cell can be given by ______ |
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Answer» SRP of ANODE - SRP of CATHODE |
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| 6215. |
{:("Elements",,"Electronegative value"),("i.F",,"(a)2.5"),("ii. Cl",,"(b) 2.8"),("iii. Br",,"(c) 3.0"),("iv. I",,"(d) 4.0"):} |
| Answer» SOLUTION :i-d, ii-c, iii-b, iv-a | |
| 6216. |
Elements with atomic numbers 90 to 103 in the Modern Periodic table are called _________ . |
| Answer» SOLUTION :ACTINIDES | |
| 6217. |
Elements showing properties of both metals and non-metals are called _________ . |
| Answer» SOLUTION :METALLIODS | |
| 6218. |
Elements of which group are called as alkalimetals? |
| Answer» SOLUTION :ELEMENTS of group 1 are CALLED alkali metals. | |
| 6219. |
Elements of which family forms anions most rreadily ? |
| Answer» Answer :A | |
| 6220. |
Elements of the second period do not have the same number of ____ but they contain the same number of ____ . |
| Answer» SOLUTION :VALENCE ELECTRONS, SHELLS | |
| 6221. |
Elements of s and p blocks are collectively called "______" |
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| 6223. |
Elements of a group and Elements of a period |
Answer» SOLUTION :
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| 6224. |
Elements in the same group of the periodic table have the same |
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Answer» atomic number |
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| 6226. |
Elements in the same period may have |
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Answer» different number of NEUTRONS |
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| 6227. |
Elements in the periodic table show periodicity of properties. List any four such properties. |
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Answer» Solution :(i) Atomic size (II) VALENCY or combining capacity (III) Metallic PROPERTY (IV) Non-metallic property. |
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| 6228. |
Elements in the same group have similar |
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| 6229. |
Elements in the Modem Periodic Table are arranged in 17 vertical columns called groups. |
| Answer» SOLUTION :FALSE -There are 18 GROUPS. | |
| 6230. |
Elements in the Modern Periodic Table are arranged in ____ vertical columns called _________. |
| Answer» SOLUTION :18, GROUPS | |
| 6231. |
Elements in a period have same |
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Answer» NUMBER of VALENCE electrons |
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| 6232. |
Elements havingthe sameatomicnumber, butdifferentmassnumberarecalled____. |
| Answer» SOLUTION :ISOTOPES | |
| 6233. |
Elements havingidentical valence shell electronicconfiguration , possess similar ____________ properties . |
| Answer» SOLUTION :CHEMICAL | |
| 6234. |
Elements have been arranged in the following sequence on the basis of their increasing atomic masses.F, Na, Mg, AI, Si, P, S, cl, Ar, K.(a) Pick two sets of elements which have similar properties.(b)The given sequence represents which law of classification of elements? |
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Answer» SOLUTION : (a) (i) F and CL (ii) NA and K (b)Newlands. LAW of Octaves |
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| 6235. |
Elements having atomic numbers 57 to 71 consistute the lanthanide series. ] |
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| 6236. |
Elements have been arranged in the following sequence on the basis of their increasing atomic masses: F, Na, Mg, Al, Si, P, S, CI, Ar, K. a] Pick two sets of elements which have similar properties. b) The given sequence represents which law of classification of elements? |
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Answer» Solution :a] Two SETS of elements that show similar properties are: F and Cl, Na and K. b] The GIVEN sequence represents elements NEWLANDS. law of octaves. As PER this law, elements are arranged in increasing order of their atomic masses and every 8TH element shows similar properties to that of the 1st element. |
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| 6237. |
Elements forming ionic compounds attain noble gas electronic configuration by either gaining or losing electrons from their valence shells. Explain giving reason why carbon cannot attain such a configuration in this manner to form its compounds. Name the type of bonds formed inionic compounds and in the compounds formedby carbon. Also explain with reason why carbon compounds are generally poor conductors of electricity. |
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Answer» Solution :Carbon has 4 electrons in its outermost shell. It cannot lose 4 electrons to form `C^(4+)` because very high energy is required to remove 4 electrons. It cannot gain 4 electrons to form `C^(4-)` ions because it is difficult for 6 protons to hold on to 10 electrons. (i) lonic/Electrovalent Bonds. (II) Covalent bonds. (iii) There are no charged partides in carbon compounds and HENCE they are poor CONDUCTORS of electricity. |
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| 6238. |
Elements have been arranged in the following sequence on the basis of their increasing atomic masses. F, Na, Mg, Al, Si, P, S, CI, Ar, K . The given sequence represents which law of classification of elements ? |
| Answer» SOLUTION :Newland.sLaw of OCTAVES | |
| 6239. |
Elements forming oxides with same type of formulae will have ______ chemical properties. |
| Answer» SOLUTION :same | |
| 6240. |
Elements have been arranged in the following sequence on the basis of their increasing atomic masses. F, Na, Mg, Al, Si, P, S, CI, Ar, K . Pick two sets of elements which have similar properties. |
| Answer» SOLUTION :SET 1 F and Cl Set 2) Na and K | |
| 6241. |
Elements forming ionic compounds attain noble gas electronic configuration by either gaining or losing electrons from their valence shells. Explain giving reason why carbon cannot attain such a configuration in this manner to form its compounds. Name the type of bonds formed in ionic compounds and in the compounds formed by carbon. Also explain with reason why carbon compounds are generally poor conductors of electricity. |
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Answer» Solution :Carbon has 4 ELECTRONS in its outermost shell. It cannot lose 4 electrons to form `C^(4+)` cationbecause very HIGH energy is required to remove 4 electrons leaving behind a carbon cation with 6 protons in its nucleus holding onto just 2 electrons. It ALSO cannot gain 4 electrons to form `C^(4-)` anion because it is difficult for 6 protons to hold onto 10 electrons. The type of bonds formed in ionic compounds are ionic or electrovalent bonds and in compounds formed by carbon are covalent bonds. Since the electrons are shared,there are no charged particles in carbon compounds and hence they are poor conductors of electricity. |
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| 6242. |
Elements belonging to the same group have the same valency. |
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Answer» Solution :(i) VALENCY is the number of electrons donated, accepted or shared by the atoms of an element so as to COMPLETE the OCTET in the outermost orbit. (ii)Valency is dependent upon the number of valence electrons present in the outermost shell of an atom called valence electrons. (iii) Elements in the same group have same number of valence electrons, irrespective of the number of orbits. HENCE, elements in the same group have the same valency. |
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| 6243. |
Elements belonging to the same group have similar chemical properties because |
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Answer» they are all metallic elements |
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| 6244. |
Elements beloging to the same group have similar properties because |
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Answer» they have SIMILAR electronic configuration of the OUTERMOST shell |
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| 6245. |
Elements are classified on the basis of similarities in their ____ . |
| Answer» SOLUTION :PROPERTIES | |
| 6246. |
Elements A, B, C, D, E, F, G, H, I, J and have atomic masses 13, 3, 97, 25, 7, 35, 9, 30, 50, and 19 respectively. According to law of octaves, which elements would have similar properties? Explain. |
Answer» Solution :ACCORDING to Newlands. law of octaves, when ELEMENTS are arranged in increasing order of atomic masses, every 8th ELEMENT has similar properties as those of the 1st element, Given elements arranged in increasing order of atomic masses:  Elements that have similar properties are the IST and 8th, 2ND and 9th, and 3rd and 10th, i.e. B-F, E-I, and G-C. |
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| 6247. |
Elements A, B, C, D and E have the electronic configura-tion as shown in the table : (i) Name the element which belongs to the 2^(nd) period. (ii) Name two elements which will exhibit a valency of 1. (iii) Name another element which will have the same valency as the element C. |
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Answer» Solution :(i) The element A belongs to the `2^(ND)` PERIOD since the electrons are filled K and L shells only. (ii) The elements B and D exhibit valency of 1. Valency of element B = 1, Valency of element D = (8 - 7) = 1. (iii) The element A has the same valency as the element C. Valency of element C = (8 - 5) = 3, Valency of element A = 3. THEREFORE, both of them have the same valency. 
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| 6248. |
Elements A, B, C and D have atomic numbers 1, 8, 11 and 19 respectively. Choose the odd element and give reasons for your answer. |
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Answer» Solution :ELEMENT B is ODD element. Elements A, C and D belong to Group 1 because they have 1 ELECTRON in the outermost SHELL. Element B does not belong to this group as this has 6 electrons in the valence shell. |
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| 6249. |
Elements A, B, C, and D have atomic numbers 1, 8, 11, and 19 respectively. Choose the odd element and give reason for your answer. |
| Answer» SOLUTION : Electronic CONFIGURATIONS are: `A to 1 , B to 2 , 6 , C to 2, 8 , 1`,and `D to 2,8,8,1`. Elements A, C, and D have one VALENCE electron each while B has 8 - 6 = 2 valence ELECTRONS. Hence, B is the odd element. | |
| 6250. |
{:("Element",Delta_iH_1^(Theta),Delta_iH_2^(Theta),"DeltaegH_1^0),(I,1681,3374,-328),(II,1008,1846,-295),(III,2372,5251,+48):} (a) The most reactive non-metal. (b) The least reactive non-metal. (c) The least reactive element. Give reasons also. |
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