This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In chromium (III) chloride, CrCl_3, chloride ions have cubic close packed arrangement and Cr (III) ions are present in the octahedral holes. What fraction of the octahedral holes is occupied ? What fraction of total number of holes is occupied ? |
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Answer» Then number of tetrahedral sites =2 n `therefore` Number of atoms P=2n `therefore` Ratio P:Q=2n:n =2 :1 , i.e., FORMULA is `P_2Q` |
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| 2. |
In ClF_(3), NF_(3)" and " BF_(3) molecules the chlorine, nitrogen and boron atoms are |
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Answer» `sp^(3)` hybridised `NF_(3)- sp^(3)` hybridisation `BF_(3) - sp^(2)` hybridisation |
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| 3. |
In chromium (III) Chloride, CrCl_(3) , Chloride ions have cubic close packed arrangement and Cr (III) ions are presnent in the octahedral holes. What fraction of the octahedral holes is occupied ? What fraction of totalnumber of holes is occupied ? |
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Answer» <P> |
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| 4. |
In chromatography, which of the following statement is Incorrect for R_f ? |
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Answer» `R_f` VALUE depends on the TYPE of chromatography. |
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| 5. |
In chromatography, if the stationary phase is solid, the basis is ............ |
| Answer» SOLUTION :ADSORPTION | |
| 6. |
In chlorophyll pigment how many number of nitrogen atoms surrounds the central 'Mg' atom ? |
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Answer» |
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| 7. |
In chlorobenzene, chlorine is ________ but _____ directing. |
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Answer» |
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| 8. |
in chlorine.^(35)CIand .^(37) CI isin3:1ratiocalculatechargeatomicmass. |
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Answer» Solution :three `.^(35) CI` and one `.^(37)CI` totalfour CI massof fourCI= 3 (35)+ 1 (37) 142 AMU atomicmass ofCI` =(142)/( 4) = 35.5`amu |
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| 9. |
In chemistry, .mole.is an essential tool for the chemical calculations. It is a basic S.I. unit adopted by the 14^(th) general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12 g of C. 1 mole of a gas at STP occupies 22.4 litre volume. Molar volume of solids and liquids is not definite. Molar mass of a substance is also called gram atomic mass or gram molar mass. The virtual meaning of mole is plenty, heap or the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. x L N_(2) gas at STP contains 3xx10^(22) molecules. The number of molecules in x L ozone at STP will be |
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Answer» `3XX10^(22)` `THEREFORE` same VOLUME implies same MOLECULES |
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| 10. |
In chemistry, .mole.is an essential tool for the chemical calculations. It is a basic S.I. unit adopted by the 14^(th) general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12 g of C. 1 mole of a gas at STP occupies 22.4 litre volume. Molar volume of solids and liquids is not definite. Molar mass of a substance is also called gram atomic mass or gram molar mass. The virtual meaning of mole is plenty, heap or the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. How many atoms are present in 49 g of H_(2)SO_(4)? |
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Answer» `7xx6.023xx10^(23)` `(1)/(2)` mole implies `(N_(0))/(2)` MOLECULES = `(N_(0))/(2)xx7` ATOMS |
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| 11. |
In chemistry, .mole.is an essential tool for the chemical calculations. It is a basic S.I. unit adopted by the 14^(th) general conference on weights and measurements in 1971. A mole contains as many elementary particles as the number of atoms present in 12 g of C. 1 mole of a gas at STP occupies 22.4 litre volume. Molar volume of solids and liquids is not definite. Molar mass of a substance is also called gram atomic mass or gram molar mass. The virtual meaning of mole is plenty, heap or the collection of large numbers. 1 mole of a substance contains 6.023xx10^(23) elementary particles like atom or molecule. Atomic mass unit (amu) is the unit of atomic mass, e.g., atomic mass of single carbon is 12 amu. The mass of one molecule of water is approximately |
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Answer» 1 g `=18xx1.66xx10^(-24)g=3xx10^(-23)g` |
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| 12. |
In chemical reaction, catayst: |
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Answer» alters the amount of the products |
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| 13. |
In CH_(4),NH_(3) and H_(2)O, the central atom undergoes sp^(3) hybridisation - yet their bond angles are different. Why ? |
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Answer» Solution :(i) In `CH_(4),NH_(3)` and `H_(2)O` the central atom undergoes `sp^(3)` hybridisation. But their bond angles are different DUE to the presence of lone pair of electrons. It can be explained by VSEPR theory. According to this theory, even though the hybridisation is same, the repulsive force between the bond pairs and lone pairs are not same. (iii) Bond pair - Bond `lt` Bond pair - Lone pair `lt` Lone pair - Lone pair so due to the varying repulsive force the bond pairs and lone pairs are distored from regular geometry and organise themselves in such a way that repultion will be minimum and stabily will be MAXIMUM. (iv) In case of `CH_(4)`, there are 4 bond pairs and no lone pair of electrons. So it remains in its regular geometry. i.e., tetrahedral with bond angle `=190^(@)28.` `H_(2)O` has 2 bond pairs and 2 lone pairs. There is large repsultion between lp-lp. Again repultion between lp-bp is more than that of 2 bond pairs. So 2 bond are more restricted to form inverted V shape (or) bent shape molecule with a bond angle of `104^(@)35.` (vi) `NH_(3)` has 3 bond pairs and 1 lone pair. There is repulsion between lp-bp. So 3 bonds are more retricted to form pyramidal shape with bond angle equal to `107^(@)18.` |
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| 14. |
In CH_(4),NH_(3) and H_(2)O the central atom undergoes sp hybridization - yet their bond angles are different. Why? |
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Answer» SOLUTION :(i) In `CH_(4),NH_(3)` and `H_(2)O` the central atom undergoes `sp^(3)` hybridisation. But their bond angles different due to the presence of lone pair of electrons. (ii) It can be EXPLAINED by VSEPR theory. According to this theory, even though the hybridisation is same, the repulsive force between the bond pairs and lone pairs are not same. (iii) Bond pair-Bond pair < Bond pair - Lone pair < Lone pair - Lone pair So due to the varying repulsive force the bond pairs and lone pairs are distorted from regular geometry and organise themselves in such a way that repulsion will be minimum and STABILITY will be maximum. (iv) In case of `CH_(4)` there are 4 bond pairs and no lone pair of electrons. So it remains in its regular geometry. i.e., tetrahedral with bond ANGLE = `109^(@)28`’. (v) H.Ohas 2 bond pairs and 2 lone pairs. There is large repulsion between Ip-ip. Again repulsion between Ip-bp is more than that of 2 bond pairs. So 2 bonds are more restricted to form inverted V shape (or) bent shape MOLECULE with a bond angle of `104^(@)35`.. (vi) NH, has 3 bond pairs and I lone pair. There is repulsion between Ip-bp. So 3 bonds are more restricted to form pyramidal shape with bond angle equal to 107° |
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| 15. |
In CH_(4),NH_(3) " and " H_(2)O the central atomundergoes sp^(3) hybridlsation - yet their bond angles are different. |
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Answer» Solution :(i) In `CH_(4), NH_(3) and H_(2)0` the central atom undergoes `sp^(3)` hybridisation. But their bond angles are different due to the presence of lone pair of electrons. (ii)It can be explained by VSEPR THEORY. According to this theory, even though the hybridisation is same, the repulsive force between the bond pairs and lone pairs are not same. (iii) Bond pair-Bond pair `lt` Bond pair - Lone pair `lt` Lone pair - Lone pair So due to the varying repulsive force the bond pairs and lone pairs are distorted from REGULAR geometry and organise themselves in such a way that repulsion will be minimum and stability will be maximum. (IV) In case of `CH_(4),`there are 4 bond pairs and no lone pair of electrons. So it remains in its regular geometry. i.e., tetrahedral with bond angle `= 109^(@) 28..` (v) `H_(2)O` has 2 bond is pairs and 2 lone pairs. There is large repulsion between lp-lp. Again repulsion between lp-bp is more than that of 2 hond pairs. So 2 bonds are more restricted Om nverted V shape (or) bent shape molecule with a bond angle of `104^(@) 35..` (vi) `NH_(3)` has 3bond pairs and I lone pair, There is repulsion between lp-bp. So 3 bonds are more restricted to form pyramidal shape with bond angle EQUAL to `107^(@) 18..` |
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| 16. |
In CH_(3)CH_(2)OH the bond that undergoes heterolytic cleavage most readily is: |
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Answer» `C-C` |
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| 17. |
InCH_(3) - underset(CH_(3))underset(|)(CH) - CH_(3) most stable radicals/ions formed on homolysis is/a. |
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Answer» `CH_(3)-UNDERSET(CH_(3)) underset(|)(CH) - CH_(2) ` |
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| 18. |
In CH_2 Cl_2the oxidation number of C is |
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Answer» `-4` |
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| 19. |
In certain respects, lithium differs from other alkali metals. The main reason for this is |
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Answer» Small size of LITHIUM atom and `LI^(+)` ion |
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| 20. |
In certain cases,the rate of reaction increase with time. This phenomenon is known as |
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Answer» INDUCED catalysis |
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| 21. |
In cell fluid, the most abundant cation is : |
| Answer» Answer :B | |
| 22. |
In catalytic oxidation of benzene vapours in presence of V_2O_5 to give maleic anhydride no ofatomic/nasent oxygens required for 1 mole of benzene is _______ |
Answer»
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| 23. |
In Castner -Kellnerusedfor preparationofsodiumcarbonate,______actsas ananode . |
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Answer» Nickelrod |
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| 24. |
In Castner - Kellner process, the cathode in the outer chamber is |
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Answer» Hg |
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| 25. |
In Castner Kellner cell, reaction at mercury cathode is |
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Answer» `2H_(2)O+2e^(-)rarr H_(2)+2OH^(-)` |
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| 26. |
In case the difference in solubilty ofhte two substances in the solvent is not very marked, ………….., involving a series of repeated vrystallizations, is carried out. |
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Answer» fractional crystallization |
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| 27. |
In case of hydrogen spectrum wave number is given by barv = R_H [(1)/(n_2^2) - 1/(n_2^2)] where n_1 lt n_2 |
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Answer» Balmer `bar(upsilon) =R.[1/(2^2) - 1/(n^2)]` |
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| 28. |
In case of hydrogen , molar volume at STP is "_______" 22.414L. |
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Answer» more than |
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| 29. |
In case of homologous series of alkanes, which one of the following statements is incorrect? |
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Answer» The numbers of the series have the general formula `C_nH_(2n+2)`, when N is an integar |
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| 30. |
In case of heteronuclear diatomics of the type AB, where A is more electronegative than B, bonding molecular orbital resembles the character of A more than that of B. The statement |
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Answer» is false As A is more electronegative, there is less enegy difference I between atomic ORBITAL of A and bonding M.O. HENCE, bonding M.O. resembles A more closely. |
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| 31. |
In case of H_(2)O_(2) in solid state the angle between the planes containing H-atoms is |
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Answer» `100^(@)` |
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| 32. |
In case of carbohydrates D, L indicates the |
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Answer» Configuration of - OH at last CHIRAL CARBON |
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| 33. |
In case of alkali metals , the covalent character decreases in the order : |
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Answer» `MI gt MBr gt MCl gt MF` |
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| 34. |
Incase of alkali metal halides, the ionic character increases in the order________ |
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Answer» MF < MCl < MBR < MI |
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| 35. |
In case, nitrogen sulphur both are present in an organic compound, sodium thiocynate is formed. If sodium fusion is carried out with excess of sodium, sodium thocyanate decomposes. Which of the following compounds is/are present in the extract after decomposition? |
| Answer» Answer :C | |
| 36. |
In Carius tube, the compound ClCH_(2)COOAg was heated with fuming HNO_(3) & AgNO_(3). After filtration and washing, a white precipitate was formed. The precipitate is |
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Answer» `Ag_(2)SO_(4)` |
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| 37. |
In Carius method, the sulphur in an organic compound is oxidised to ............. . |
| Answer» SOLUTION :`H_(2)SO_(4)` | |
| 38. |
In carius method of estimation of halogens, 250 mg of organic compound gave 141 mg of AgBr. Th percentage of bromine in the compound is (at mass Ag = 108 , Br = 80) |
| Answer» Solution :`%Br = (80)/(188) xx (0.141)/(0.250) xx 100 = 24` | |
| 39. |
In Carius method of estimation of sulphur 0.466g of organic compound gave 0.233 g of BaSO_(4).The percentage of sulphur is |
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Answer» 6.9 |
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| 40. |
In Carius method of estimation of halogens, 250 g of an organic compound gave 141 mg of AgBr. The percentage of bromine in the compound is: (at. Mass Ag = 108, Br = 80) |
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Answer» 24 |
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| 41. |
In Carius method of estimation of halogen, 0.15 g of an organic compound gave 0.12g of AgBr. Find out the percentage of bromine in the compound (Ag = 108, Br= 80) |
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Answer» Solution :molar MASS of AgBr `= 108 + 80 = 188g mol^(-1)` <BR> `underset(80g)(Br) + Ag rarr underset(188g)(AgBr)` 188g AgBr CONTAINS 80g Br `:.` 0.12g AgBr contains, mass of `Br = (0.12g xx 80)/(188)` |
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| 42. |
In carius method for the quantitative estimation of sulphur, it is estimated by |
| Answer» Solution :Sulphur is quantitatively estimated y `BaSO_(4)` | |
| 43. |
In Carius method for the quantitative estimation of phosphorous, by using magnesia mixture, phosphorous is estimatied by : |
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Answer» `MgNH_(4).PO_(4)` |
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| 44. |
In Carius method 0.468 g of a compound afforded 0.668 g barium sulphate. Find the percentage of S in the compound. |
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Answer» |
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| 45. |
In Carium method of estimation of halgoen, 0.15 g of an organic compound gave 0.12 g of AgBr. What is the percentage of bromine in the compound? |
| Answer» Solution :Molar mass of `AgBr=108+80=188" g "mol^(-1)` LTBR Percentage of `Br_(2)=(80)/(188)XX(0.12)/(0.15)xx100=34.04%` | |
| 46. |
In Carius method, 0.1890 g of an organic compound gave 0.2870 of silver chloride. Calculate the percentage of chlorine in the compound |
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Answer» SOLUTION :WEIGHT of SUBSTANCE = 0.1890g Weight of silver CHLORIDE = 0.2870g % of chlorine `= ("Weight of " AgCl xx 35.5 xx 100)/("weight of substance " xx 143.5) = (0.2870 xx 35.5 xx 100)/(0.1890 xx 143.5) = 37.8` |
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| 47. |
In Carius method of estimation of halogen, 0.15 g of an organic compound gave 0.12 g of AgBr. Find out the percentage of bromine in the compound. |
| Answer» SOLUTION :`BR = 34.04%` | |
| 48. |
In carious method of estimation of halogen 0.15 g of an organic compound gave 0.12 g of AgBr. Find the percentage of bromine in the compound. |
| Answer» SOLUTION :`BR = 34.04%` | |
| 49. |
In carious method 0.12g AgBr obtained from 0.15g organic compound. Find out the percentage of AgBr in compound. (Ag= 108, Br =80) |
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Answer» Solution :`underset(80g)(BR) RARR underset(188g)(AGBR)` Thus, 188g AgBr CONTAIN 80gm BROMINE. So, 0.120g AgBr contain, Bromine `= (80 xx 0.12)/(188)` % `Br = (80)/(188) xx (0.12)/(0.15) xx 100= 34.04%` |
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