NCERT Exemplar

Match the compounds given in Column I with the oxidation state of cobalt present in it (given in Column II) and assign the correct code. with the oxidation state of cobalt present in it (given in Column II) and assign the correct code.

  Solution: \[\left( c \right)\text{ }\left( A\text{ }\to \text{ }5 \right),\text{ }\left( B\text{ }\to \text{ }1 \right),\text{ }\left( C\text{ }\to \text{ }4 \right),\text{ }\left( D\text{...

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Match the coordination compounds given in Column I with the central metal atoms given in Column II and assign the correct code : Code : (i) A (5) B (4) C (1) D (2) (ii) A (3) B (4) C (5) D (1) (iii) A (4) B (3) C (2) D (1) (iv) A (3) B (4) C (1) D (2)

Solution: \[\left( b \right)\text{ }\left( A\text{ }\to 5 \right),\text{ }\left( B\text{ }\to \text{ }4 \right),\text{ }\left( C\text{ }\to \text{ }1 \right),\text{ }\left( D~\to 2 \right)\]  ...

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An aqueous pink solution of cobalt(II) chloride changes to deep blue on the addition of an excess of HCl. This is because____________. (a) [Co(H2O)6]2+ is transformed into [CoCl6]4– (b) [Co(H2O)6]2+ is transformed into [CoCl4]2– (c) tetrahedral complexes have smaller crystal field splitting than octahedral complexes. (d) tetrahedral complexes have larger crystal field splitting than octahedral complex.

Solution: (b, c) Aqueous pink arrangement of cobalt (II) chloride is because of electronic progress of electron from t2g to eg energy level of [Co(H2O)6]2+ complex. At the point when overabundance...

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Due to the presence of ambidentate ligands coordination compounds show isomerism. Palladium complexes of the type [Pd(C6H5)2(SCN)2] and [Pd(C6H5)2(NCS)2] are (a) linkage isomers (b) coordination isomers (c) ionisation isomers (d) geometrical isomers

Solution: (a) The ligands having two distinctive holding locales are known as ambident ligands e.g., NCS, NO2, and so forth Here, NCS has two restricting locales at N and S. Subsequently, NCS...

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The stabilisation of coordination compounds due to chelation is called the chelate effect. Which of the following is the most stable complex species? (a) [Fe(CO)5] (b) [Fe(CN)6]3– (c) [Fe(C2O4)3]3– (d) [Fe(H2O)6]3+

Solution: (c) arrangement of cycle by linkage between metal particle and ligand balances out the coordination compound. The ligand which chelates the metal particle are known as chelating ligand....

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When 0.1 mol COCl3(NH3)5 is treated with excess of AgNO3, 0.2 mol of AgCl are obtained. The conductivity of solution will correspond to (a) 1:3 electrolyte (b) 1:2 electrolyte (c) 1:1 electrolyte (d) 3:1 electrolyte

Solution: (b) One mole of AgNO3 accelerates one mole of chloride particle. In the above response, when 0.1 mole COCl3(NH3)5 is treated with abundance of AgNO3, 0.2 mole of AgCl are obtained hence,...

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The colour of the coordination compounds depends on the crystal field splitting. What will be the correct order of absorption of wavelength of light in the visible region, for the complexes, [Co(NH3)6]3+, [Co(CN)6]3–, [Co(H2O)6]3+ (a) [Co(CN)6]3–> [Co(NH3)6]3+>[Co(H2O)6]3+ (b) [Co(NH3)6]3+> [Co(H2O)6]3+> [Co(CN)6]3– (c) [Co(H2O)6]3+> [Co(NH3)6]3+> [Co(CN)6]3– (d) [Co(CN)6]3–> [Co(NH3)6]3+> [Co(H2O)6]3+

Solution:  

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A coordination compound CrCl3.4H2O hastens silver chloride when treated with silver nitrate. The molar conductance of its answer relates to a sum of two particles. Compose the primary recipe of the compound and name it.

Solution: Assuming it structures silver chloride, there is without one chlorine iota outside the coordination circle. The primary recipe must be [Cr(H2O)4Cl2]Cl. The name of this complex is...

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An answer of KMnO4 on decrease yields either lackluster arrangement or an earthy colored encourage or a green arrangement relying upon the pH of the arrangement. What various phases of the decrease do these address and how are they completed?

Solution: In acidic medium, permanganate changes to manganous particle which is lackluster.   \[MnO4-+8H+\text{ }+\text{ }5e-\to \text{ }Mn2+\text{ }+\text{ }4H2O\] (drab)   In basic...

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At the point when an orange arrangement containing Cr2O72–particle is treated with an antacid, a yellow arrangement is framed and when H+ particles are added to a yellow arrangement, an orange arrangement is acquired. Clarify for what reason does this occur?

Solution: At the point when Cr2O72–is treated with an antacid:   \[\left( orange \right)\text{ }Cr2O72+\text{ }OH-\to \text{ }2CrO42-\left( yellow \right)\] At the point when the yellow...

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At the point when an earthy colored compound of manganese (A) is treated with HCl it gives a gas (B). The gas taken in abundance responds with NH3 to give an unstable compound (C). Distinguish intensifies A, B and C.

Solution: At the point when earthy colored co pound of manganese (A) is treated with HCl it gives chlorine gas.   \[MnO2\text{ }+\text{ }4HCl\text{ }\to \text{ }MnCl2\text{ }+\text{ }Cl2\text{...

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In spite of the fact that +3 is the trademark oxidation state for lanthanoids however cerium additionally shows +4 oxidation state in light of the fact that (a) it has variable ionization enthalpy (b) it tends to accomplish respectable gas design (c) it tends to accomplish f° arrangement (d) it looks like Pb4+

Solution: (b, c) Cerium shows +4 oxidation state likewise on the grounds that it tends to accomplish respectable gas setup and achieve f° design. Ce – 4f15d'6s2 (Ce4+–4f°)

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As dichromate, Cr (VI) is a solid oxidizing specialist in acidic medium however, Mo (VI) in MoO3 and W (VI) in WO3 are not on the grounds that (a) Cr (VI) is more steady than Mo(VI) and W(VI) (b) Mo(VI) and W(VI) are more steady than Cr(VI) (c) higher oxidation conditions of heavier individuals from bunch 6 of change series are more steady (d) lower oxidation conditions of heavier individuals from bunch 6 of change series are more steady

Solution: (b, c) In d-block components, for heavier components, the higher oxidation states are more steady. Thus, Mo(VI) and W(VI) are more steady than Cr (VI). That is the reason, Cr (VI) as...

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For what reason is HCl not used to make the medium acidic in oxidation responses of KMnO4 in acidic medium? (a) Both HCl and KMn04 go about as oxidizing specialists. (b) KMnO4 oxidizes HCl into Cl2 which is likewise an oxidizing specialist. (c) KMnO4 is a more fragile oxidizing specialist than HCl. (d) KMnO4 goes about as a decreasing specialist within the sight of HCl.

Solution: (b) HCl isn't utilized to make the medium acidic in oxidation responses of KMnO4 in acidic medium. The explanation is that in case HCl is utilized, the oxygen delivered from KMnO4 + HCl is...

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In spite of the fact that zirconium has a place with 4d change series and hafnium to 5d change series and still, after all that they show comparative physical and substance properties in light of the fact that (a) both have a place with d-block (b) both have same number of electrons (c) both have comparative nuclear span (d) both have a place with a similar gathering of the intermittent table

Solution: (c) Zirconium and hafnium have comparable nuclear range thus they show comparable physical and synthetic properties.

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Most elevated oxidation condition of manganese in fluoride is +4 (MnF4) however most noteworthy oxidation state in oxides is +7 (Mn2O7) in light of the fact that (a) fluorine is more electronegative than oxygen (b) fluorine doesn’t have d-orbitals (c) fluorine settles lower oxidation state (d) in covalent mixtures fluorine can frame single bond just while oxygen shapes twofold bond

Solution: (d) The most noteworthy oxidation condition of manganese in fluoride is +4 (MnF4) yet in oxides it is +7 (Mn2O7) in light of the fact that in covalent mixtures fluorine can frame single...

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Which of the accompanying assertion isn’t right? (a) Copper frees hydrogen from acids (b) In its higher oxidation states, manganese structures stable mixtures with oxygen and fluorine (c) Mn3+ and Co3+ are oxidizing specialists in watery arrangement (d) Ti2+ and Cr2+ are decreasing specialists in watery arrangement

Solution: (a) Copper doesn't free hydrogen from acids. \[\begin{array}{*{35}{l}} Cu\text{ }+\text{ }2H2S04\text{ }\text{ }>\text{ }CuSO4\text{ }+\text{ }S02\text{ }+\text{ }2H2O  \\ ~  \\...

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Interstitial mixtures are shaped when little particles are caught inside the gem cross section of metals. Which of coming up next isn’t the trademark property of interstitial mixtures? (a) They have high liquefying focuses in contrast with unadulterated metals (b) They are exceptionally hard (c) They hold metallic conductivity (d) They are synthetically extremely receptive.

Solution: (d) Interstitial mixtures are synthetically idle.

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At the point when KMnO4 arrangement is added to oxalic corrosive arrangement, the decolourisation is delayed to start with yet becomes momentary after some time on the grounds that (a) CO2 is shaped as the item (b) Reaction is exothermic (c) Mn04 catalyzes the response (d) Mn2+ goes about as autocatalyst

Solution: (d) When KMnO4 arrangement is added to oxalic corrosive arrangement, the decolourisation is delayed first and foremost yet becomes immediate after some time in light of the fact that Mn2+...

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In a cricket tournament 16 school teams participated. A sum of Rs 8000 is to be awarded among themselves as prize money. If the last placed team is awarded Rs 275 in prize money and the award increases by the same amount for successive finishing places, how much amount will the first place team receive?

Solution: Let the sum got by the lead position group be a Rs and d be distinction in sum As the thing that matters is same subsequently the runner up will get a – d and the third spot a – 2d, etc...

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In a potato race 20 potatoes are placed in a line at intervals of 4 metres with the first potato 24 metres from the starting point. A contestant is required to bring the potatoes back to the starting place one at a time. How far would he run in bringing back all the potatoes?

Solution: Given at start he needs to run 24m to get the main potato then 28 m as the following potato is 4m away from first, and so on Thus the succession of his running will be 24, 28, 32 … There...

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A side of an equilateral triangle is 20cm long. A second equilateral triangle is inscribed in it by joining the mid points of the sides of the first triangle. The process is continued as shown in the accompanying diagram. Find the perimeter of the sixth inscribed equilateral triangle.

Solution: Say ABC is a triangle with $AB\text{ }=\text{ }BC\text{ }=\text{ }AC\text{ }=\text{ }20$ cm Let’s say that D, E and F are respectively the midpoints of AC, CB and AB  that are joined to...

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We know the sum of the interior angles of a triangle is 180°. Show that the sums of the interior angles of polygons with 3, 4, 5, 6, … sides form an arithmetic progression. Find the sum of the interior angles for a 21-sided polygon.

Solution: It is given that the sum of interior angles of a polygon having ‘n’ sides is denoted by $(n-2)\times {{180}^{\circ }}$ The sum of angles having 3 sides i.e n $=\text{ }3\text{ }is\text{...

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A man accepts a position with an initial salary of Rs 5200 per month. It is understood that he will receive an automatic increase of Rs 320 in the very next month and each month thereafter. (a) Find his salary for the tenth month (b) What is his total earnings during the first year?

Solution: It is given to us that in first month the man’s salary is Rs.5200 and then it increases by Rs.320 every month Therefore, 5200, 5200 + 320, 5200 + 640… will be the sequence so formed of his...

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A five digit number divisible by 3 is to be formed using the numbers 0, 1, 2, 3, 4 and 5 without repetitions. The total number of ways this can be done is A. 216 B. 600 C. 240 D. 3125 [Hint:5 digit numbers can be formed using digits 0, 1, 2, 4, 5 or by using digits 1, 2, 3, 4, 5 since sum of digits in these cases is divisible by 3.]

Solution: Option (A) 216 is correct Explanation: Using digits $0,1,2,4,5$ the 5-digit numbers that can be formed $$\begin{tabular}{|l|l|l|l|l|} \hline 4 & 4 & 3 & 2 & 1 \\ \hline \end{tabular}$$ $4...

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A swimming pool is to be drained for cleaning. If L represents the number of litres of water in the pool t seconds after the pool has been plugged off to drain and L = 200 (10 – t)2. How fast is the water running out at the end of 5 seconds? What is the average rate at which the water flows out during the first 5 seconds?

Given, \[L\text{ }=\text{ }200\left( 10\text{ }\text{ }t \right)2\] where L addresses the quantity of liters of water in the pool. On separating both the sides w.r.t, t, we get \[dL/dt\text{...

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