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. |
Neither q nor w is a state function but q + w is a state function.Explain why? |
| Answer» Solution :Both Q and w are not state FUNCTION but `q + w` is EQUAL to `DELTAU` which is state function. | |
| 2. |
Neils Bohr was the first to explain quantitatively the general features of hydrogen atom structure and its spectrum. Calculate the wave number of radiation due to transition of an electron from fourth orbit to second orbit (R_h=109677cm^-1) |
| Answer» SOLUTION :`_V^-=R_H[1/(n_1^2)-1/n_2^1]=109677[1/2^2-1/4^2]=109677xx3/16=2.05xx10^6m^(-1)` | |
| 3. |
Negatively charged carbon species having eight electrons in its outermost orbit is called as |
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Answer» carbonium ion |
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| 4. |
Negative soil pollution is |
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Answer» Reduction is soil productivity DUE to erosion and over use |
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| 5. |
Negative catalyst is that which |
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Answer» takes the REACTION in BACKWARD direction |
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| 6. |
Negative catalyst for the decomposition of H_2O_2 is |
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Answer» SILICA |
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| 7. |
Necessary conditions for spontanity of a reaction ________ |
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Answer» `(G)_("products") lt (G)_("reactants")` `Delta G lt 0 RARR (Delta H)_(S.T) lt 0 rArr (Delta H)_(S.P) lt 0` `Delta S_("universe") gt 0 rArr` So Ans a, c, d |
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| 8. |
Necessary conditions for Fiels-Alder reactions are : |
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Answer» `(I),(II),(III)` |
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| 9. |
NCl_(3) is an endothermic compound while NF_(3) is an exothermic compound. |
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Answer» Solution :DUE to smaller size of F as compared to Cl, the N-F bond is much stronger `(272k kJ MOL^(-1))` than N-Cl bond `(201 kJ mol^(-1))` while bond dissociation energy of `F_(2)(158.8 kJ mol^(-1))` is much lower than that of `Cl_(2)(242.6 kJ mol^(-1))`. Therefore, energy RELEASED during the formation of `NF_(3)` molecule is more than the energy needed to break `N_(2)(941.4 kJ mol^(-1))` and `F_(2)` molecules into individual ATOMS. In other words formation of `NF_(3)` is an exothermic reaction or `NF_(3)` is an exothermic compoud. `{:(N_(2)(g)+3F_(2)(g)to2NF_(3)(g),,DeltaH=-214.2Jmol^(-)),(N_(2)(g)+3Cl_(2)(g)to2NCl_(3)(g),,DeltaH=-463.2kJmol^(-1)):}` In contrast, energy released during the formation of `NCl_(3)` molecule is les than the energy needed to break `N_(2)andCl_(2)` molecules into individual atoms. In other words, formation of `NCl_(3)` is an endothermic reaction or `NCl_(3)` is an endothermic compound. |
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| 10. |
NCl_(3) gets hydrolysed to from NH_(3)andHOCl while PCl_(3) on hydrolysis gives H_(3)PO_(3)andHCl. Explair why ? |
Answer» Solution :N does not have d-orbitals to accommodate the ELECTRONS donated by Oof `H_(2)O`, therefore, attack of `H_(2)O` OCCURS on the Cl atom which has d- orbitals to accommodate the extra electrons donated by `H_(2)O` Consequently, Cl-O bond is FORMED LEADING to the FORMATION of `HOClandNH_(3)` as shown below : In contrast, both P and Cl have d- orbitals to accommodate electrons by `H_(2)O`. But P-O bond much stronger than Cl-O bond. As a result, attack of `H_(2)O` molecules occurs preferentially on P of PC to form `H_(3)PO_(3)andHCl`.
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| 11. |
NCl_(3) gets readily hydrolysed while NF_(3) does not. Why ? |
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Answer» Solution :In `NCl_(3)`, Cl has vacant d-orbitals to accept the lone PAIR of electrons donated by O-atom of `H_(2)O` molecule but in `NF_(3)`, F does not have d-orbitals. Thus, `NCl_(3)` undergoes hydrolysis but `NF_(3)` does not. `NCl_(3)+3H_(2)OtoNH_(3)+HOCl","NF_(3)+H_(2)Oto` No REACTION |
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| 12. |
(NCERT Examplar Problem) Molecular orbitals are formed by the overlap of atomic orbitals . Two atomic orbitals combine to form two molecular orbitals called bonding molecular orbital (BMO) and antibonding molecular orbital (ABMO) . Energy of antibonding orbitals is raised above the parent atomic orbitals that have combined and the energy of the bonding orbitals is lowered than the parent atomic orbitals . Energies of verious molecular orbitals for elements hybrogen to nitrogen increase in the order : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt (pi_(2p_(x)) = pi_(2p_(y))) lt sigma2p_(z) lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) and for oxygen and fluorine , order of energy of molecular orbitals is given below : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt sigma 2p_(x) lt (pi_2p_(x) = pi_2p_(y))lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) Different atomic orbitals of one atom combine with those atomic orbitals of the second atom which have comparable energies and proper orientation . Further , if the overlapping is headon, the molecular orbital is called 'sigma', (sigma) and if the overlap is lateral, the molecular orbitals is called 'pi' , (pi) . The molecular orbitalsare filled with electrons according to the same rules as followed for filling ofatomic orbitals . However, the order for filling is not Whihc of the following statements is correct ? |
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Answer» In the formation of dioxygen form OXYGEN atoms, 10 molecular orbitals will be formed. `sigma_((1s)/(1))^(2) sigma_((1s)/(2))^(**2) sigma_((2s)/(3))^(2) sigma_((2s)/(4))^(**2) sigma_((2p_(z))/(5))^(2) pi_((2p_(X))/(6))^(2)pi_((2p_(y))/(7))^(2)pi_((2p_(x))/(8))^(**1)pi_((2p_(y))/(9))^(**1)pi_((2p_(z))/(10))^(**0)` |
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| 13. |
(NCERT Examplar Problem) Molecular orbitals are formed by the overlap of atomic orbitals . Two atomic orbitals combine to form two molecular orbitals called bonding molecular orbital (BMO) and antibonding molecular orbital (ABMO) . Energy of antibonding orbitals is raised above the parent atomic orbitals that have combined and the energy of the bonding orbitals is lowered than the parent atomic orbitals . Energies of verious molecular orbitals for elements hybrogen to nitrogen increase in the order : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt (pi_(2p_(x)) = pi_(2p_(y))) lt sigma2p_(z) lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) and for oxygen and fluorine , order of energy of molecular orbitals is given below : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt sigma 2p_(x) lt (pi_2p_(x) = pi_2p_(y))lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) Different atomic orbitals of one atom combine with those atomic orbitals of the second atom which have comparable energies and proper orientation . Further , if the overlapping is headon, the molecular orbital is called 'sigma', (sigma) and if the overlap is lateral, the molecular orbitals is called 'pi' , (pi) . The molecular orbitalsare filled with electrons according to the same rules as followed for filling ofatomic orbitals . However, the order for filling is not In whihc of the following moelcular,sigma 2p_(z), molecular orbitals is filled afterpi 2p_(x) and pi 2p_(y) molecular orbitals ? |
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Answer» `O_(2)` |
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| 14. |
(NCERT Examplar Problem) Molecular orbitals are formed by the overlap of atomic orbitals . Two atomic orbitals combine to form two molecular orbitals called bonding molecular orbital (BMO) and antibonding molecular orbital (ABMO) . Energy of antibonding orbitals is raised above the parent atomic orbitals that have combined and the energy of the bonding orbitals is lowered than the parent atomic orbitals . Energies of verious molecular orbitals for elements hybrogen to nitrogen increase in the order : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt (pi_(2p_(x)) = pi_(2p_(y))) lt sigma2p_(z) lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) and for oxygen and fluorine , order of energy of molecular orbitals is given below : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt sigma 2p_(x) lt (pi_2p_(x) = pi_2p_(y))lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) Different atomic orbitals of one atom combine with those atomic orbitals of the second atom which have comparable energies and proper orientation . Further , if the overlapping is headon, the molecular orbital is called 'sigma', (sigma) and if the overlap is lateral, the molecular orbitals is called 'pi' , (pi) . The molecular orbitalsare filled with electrons according to the same rules as followed for filling ofatomic orbitals . However, the order for filling is not Which of the followingpair is expected to have the same bond order ? |
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Answer» `O_(2), N_(2)` `N_(2)^(+) = 2.5 , O_(2)^(-) = 1.5, N_(2)^(-) = 2.5` |
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| 15. |
(NCERT Examplar Problem) Molecular orbitals are formed by the overlap of atomic orbitals . Two atomic orbitals combine to form two molecular orbitals called bonding molecular orbital (BMO) and antibonding molecular orbital (ABMO) . Energy of antibonding orbitals is raised above the parent atomic orbitals that have combined and the energy of the bonding orbitals is lowered than the parent atomic orbitals . Energies of verious molecular orbitals for elements hybrogen to nitrogen increase in the order : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt (pi_(2p_(x)) = pi_(2p_(y))) lt sigma2p_(z) lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) and for oxygen and fluorine , order of energy of molecular orbitals is given below : sigma 1s lt sigma ^(**)1s lt sigma 2s lt sigma^(**)2s lt sigma 2p_(x) lt (pi_2p_(x) = pi_2p_(y))lt (pi^(**)2p_(x) = pi^(**) 2p_(y)) lt sigma^(**) 2p_(z) Different atomic orbitals of one atom combine with those atomic orbitals of the second atom which have comparable energies and proper orientation . Further , if the overlapping is headon, the molecular orbital is called 'sigma', (sigma) and if the overlap is lateral, the molecular orbitals is called 'pi' , (pi) . The molecular orbitalsare filled with electrons according to the same rules as followed for filling ofatomic orbitals . However, the order for filling is not Which of the following molecular orbitals has maximum number of nodal planes ? |
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Answer» `sigma^(**)1S` `sigma_(1s)^(**)= 1, sigma_(2p_(z))^(**) = 1 , pi_(2p_(x)) = 1, pi_(2p_(y))^(**) = 2 ` |
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| 16. |
NBS is a specific reagent for |
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Answer» NUCLEOPHILIC SUBSTITUTION reaction |
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| 17. |
Nbenzeen reacts with hydrogen in the presence of pt to yield |
| Answer» SOLUTION :CYCLOHEXANE | |
| 18. |
Nature of Sb_4O_6 is |
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Answer» ACIDIC |
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| 19. |
Nature of CO_(2) and SiO_(2) are respectively |
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Answer» ACIDIC, Basic |
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| 20. |
The nature of 0.1 M solution of sodium bisulphate is |
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Answer» Acidic |
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| 21. |
Natural sources of air pollution are ? |
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Answer» Volcanic eruptions |
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| 22. |
Natural abundance of heavy water in water is 1: 6000. How many heavy water molecules are present in one drop of water ? (one mL water is 20 drops) |
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Answer» Solution :ONE mL water =one gram (d=1 g per mL) weight of one drop of water `=(1)/(20)g` weight of `D_(2)O` in one drop of water `=(1)/(20 xx 6000)g` Number of moles of `D_(2)O =("weight")/(GMW)=(1)/(20 xx 6000 xx 20)` Number of `D_(2)O` molecules =Number of moles `xx N_(A)` `=(6.022 xx 10^(23))/(20 xx 6000 xx 20)=2.51 xx 10^(17)` Number of HEAVY water molecules is `2.51 xx 10^(17)` |
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| 23. |
Native silver metal forms a water soluble complex with a dilute solution of NaCN in the presence of |
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Answer» nitrogen |
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| 24. |
Nassler's reagent is : |
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Answer» `NaHgCl_(4)` |
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| 25. |
Nascent hydrogen consists of..... |
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Answer» Hydrogen ATOMS with excess energy |
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| 26. |
Nascent hydrogen consists of |
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Answer» HYDROGEN ions in the EXCITED state |
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| 27. |
Nascent hydrogen consists of: |
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Answer» Hydrogen atoms with excess energy |
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| 28. |
Napthalene is an aromatic compound justify the statement using Huckle rule. |
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Answer» <P> Solution :ACCORDING to Hucle rule, if NAPHTHALEIN is an aromic compound it should posses `(4n+2)pi` electrons delocalized in the RING.In naphthalein `n=2` Number of delocalized p electrons `=(4n+2)=4xx2+2` `=10pi` electrons Hence naphthalein is an aromatic compound. |
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| 29. |
Napthalene is a/an |
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Answer» Ionic SOLID |
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| 30. |
Naphthalene is an aromatic compound. |
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Answer» |
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| 31. |
Naphthalene is a volatile solid. It is best purified by : |
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Answer» crystallisation |
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| 32. |
NaOH(Solid)+Cooverset(200^(@)C)rarrX, product X is : |
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Answer» `NaHCO_(3)` |
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| 33. |
NaOH_((aq)) + HCl_((aq)) rarr NaCl_((aq)) + H_(2)O, Delta H= -13.6 Kcal. H_(2(g)) + (1)/(2) O_(2(g)) rarr H_(2)O , Delta H = - 68 Kcal. What is hat of formation of OH^(-) ? |
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Answer» `-54.4` KCAL `OH^(-) + H^(+) rarr H_(2)O, Delta H = -13.6` `Delta H = Delta H_(f_(H_(2)O)) - Delta H_(f_(OH^(-))) rArr - 13.6 = - 68- Delta H_(f_(OH^(-)))` `Deta H_(f_(OH^(-))) = -54.4` Kcal |
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| 35. |
NaOH liberates NH_(3) with |
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Answer» `NH_(4)Cl` |
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| 37. |
NaOH+D_(2)OrarrNaOD+HDO is known as |
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Answer» EXCHANGE reaction |
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| 38. |
NaOH+D_(2)O rarr NaOD+HDO is known as |
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Answer» EXCHANGE reaction |
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| 39. |
NaOH +D_(2) to NaOD+HDO is known as |
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Answer» EXCHANGE reaction |
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| 40. |
NaOH+Counderset(5-10 atm)overset(200^(@)C)rarrA. The product A is |
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Answer» HCOONa |
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| 41. |
NaOH and Na_(2)CO_(3) are dissolved in 200ml aqueous solution. Now methyl orange is added in the same solution titrated and requires 2.5ml of the same HCl. Calculate the normality of NaOH & NaCO_(3). |
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Answer» `(0.5)/(200),(1.5)/(200)` With phenolphthalein, `eq_(HCl)` = `eq_(NaOH)+(1)/(2)eqNa_(2)CO_(3)` `17.5xx0.1=axx1+bxx1` With methyl organe, `eq_(HCl)=(1)/(2)eqNa_(2)CO_(3)` `2.5xx0.1=bxx1` `implies a=1.5,b=0.25` implies `[NaOH]=(1.5)/(200)M=(1.5)/(200)N` `[Na_(2)CO_(3)]=(0.25)/(200)M=(0.5)/(200)N` |
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| 42. |
NaNO_(3) overset(500^(@)C)rarr (A)+(B) (A) overset(800^(@)C)rarr (C)+(D)+(E) Find the number of correct statements: (a) Compound (B) is paramagnetic in nature (b) Compound (B) when undergoes dimerisation the dimer product is diamagnetic in nature (c) Bond order of compound (B) is two (d) (D) is N_(2) gas (e) Compound (B) and (E) are same gas |
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Answer» (C) `rarr Na_(2)O` (D) `rarr N_(2)` (E) `O_(2)` |
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| 43. |
NaNO_(3)overset(500^(@)C)rarrA+X_((g)) , A+NH_(2)CONH_(2)+H^(+)rarrY_((g))+z_((g))+H_(2)O. What are the gases X, Y and Z ? |
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Answer» Solution :`2NaNO_(3)overset(500^(@)C)rarr2NaNO_(2)+O_(2)` `2NaNO_(2)+NH_(2)CONH_(2)+2H^(+)rarr2N_(2)+CO_(2)+3H_(2)O+2Na^(+)` X is `O_(2)` , Y is `N_(2)` and Z is `CO_(2)` |
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| 44. |
Names of some compounds are given. Which one is not in IUPAC system ? |
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Answer» `{:(""CH_(3)),("|"),(CH_(3)-CH_(2)-CH_(2)-CH-CH-CH_(2)CH_(3)),("|"),(""CH_(2)CH_(3)),("3-Methyl-4-ethylheptane"):}` |
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| 46. |
Name twophenomena that can be explained on the basis of surface tension. |
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Answer» SOLUTION :Two phenomena that can be explained on the basis of surface TENSION are as FOLLOWING. (i) Rise or FALL of the LIQUID in a capillary (capillary action). (ii) Spherical shape of small liquid drops. |
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| 47. |
Name two types of hydrogen bonding. |
| Answer» SOLUTION :Inter molecular and INTRA molecular HYDROGEN BOND. | |
| 48. |
Name two solvents which are commonly used to dissolve organic solids. |
| Answer» SOLUTION :ETHYL ALCOHOL and ANHYDROUS ETHER. | |
| 49. |
Name two phenomena that can be explained on the basis of surface tension. |
| Answer» Solution :Surface tension can explain (i) CAPILLARY ACTION, i.e., RISE or FALL of a liquid in a capillary, (ii) spherical shape of small liquid drops. | |
| 50. |
Name two methods which can be safely used to purify aniline. |
| Answer» SOLUTION :VACUUM DISTILLATION and STEAM distillation. | |