General Questions and Answers

For of the Original Buffer Solution 1 00 mL 6 00 M NaOH irading 1 point each for the six calculation cells below 6 points total Total Volume of Solution measured NaOH calc d after dilution before neutralization HOAC calc d after dilution before neutralization OAC calc d after dilution before neutralization HOAc calc d after neutralization OAC calc d after netutraliation pH calculated pH measured 32 2 1 33 2 mL 197

The radius of cation is r anion is r Z is nuclear charge of anion Zc is nuclear charge of cation S is screening constant Which of the following is correct TZ S Z S B 220 rc Z S Z S C TZ rc Z S D a Ze TZ

116 Among LiCl BeCl2 BC13 and CC14 the covalent bond character follows the order 1 LiCl BeCl BC1 CCl4 2 LICI BeCl BC13 CC14 3 LiCl BeCl BCl CCl4 4 LICI BeCh BCI CCl4

The second ionisation potentials in electron volts of oxygen and fluorine atoms are respectively give A 35 1 38 3 C 38 3 35 1 D 35 1 35 1 B 38 3 38 3

JEE Mains 20 1 C3H O3 2 C H O 3 C H O The percentage composition of carbon by mole in methane is 1 75 2 80 3 20 Tu 4 C H O JEE Main Online 4 25 molar mass of 1 H 1 g mol and C

15 Under the same reaction conditions initial concentration of 1 386 mol dm3 of a substance becomes half in 40 seconds and 20 seconds through first order and zero order kinetics respectively Ratio k k of the rate constants for first order k and zero order k of the reactions is 1 0 5 mol dm 2 1 0 mol dm 0 693 3 1 5 mol dm 3 4 2 0 mol dm 2 86 x 1 1 386 4 0 0255 min fraffeatt 1 386 mol dm 40 Fri Fraich k k k 20 A 1 0 5 mot dm 2 1 0 mol dm 3 1 5 mol dm 4 2 0 mot1 dm3 ct kofe no 215

Arrange the elements with the following electronic configurations in increasing order of electron affinity i 1s 2s 2p5 iii 1s 2s 2p a i i iii iv c iii ii iv i ii 1s 2s 2p iv 1s 2s 2p b d ii iii i iv 3s 3p iv iii ii i

3 2 0 of mixture involving Na3PO4 Na2HPO4 or NaH PO4 or involving three of them The solution is titrated with 16 5 mL of 0 5 M HCI to reach bromocresol green end point The same solution is also titrated with 7 6 mL of 0 7 M NaOH to reach phenolphthalein end point What is the composition of that mixture What are the amounts of species in the mixture H 1 0078 0 15 99 Na 22 98 P 30 974

130 In photoelectric effect the kinetic energy photoelectrons increases linearly with the 1 Wavelength of incident light 2 Frequency of incident light 3 Velocity of incident light 4 Atomic mass of an element 121 01

1 0 01 M 2 0 001 M 3 0 1 M 4 0 02 M An excess of AgNO3 is added to 100 mL of a 0 01 M solution of dichlorotetraaquachromium III chloride The number of moles of AgCl precipit AAJ KA TOPPER 3 0 01 would be 1 0 002 2 0 003 4 0 001

7 The correct order of the basic strength of methy substituted amines in aqueous solution is 1 CH NH CH NH CH N 2 CH NH CH NH CH s N 3 CH3 3 N CH3NH CH3 2NH 4 CH N CH N CH NH

6 Nitrobenzene on reaction with conc HNO3 H SO4 at 80 100 C forms which one of the following products 1 1 3 Dinitrobenzene 2 1 4 Dinitrobenzene 3 1 2 4 Trinitobenzene 1 2 Dinitrobenzene 4

A cylinder containing an ideal gas 0 1 mol of 1 0 dm is in thermal equilibrium with a large volume of 0 5 molal aqueous solution of ethylene glycol at its freezing point If the stoppers S and S as shown in the figure are suddenly withdrawn the volume of the gas in litres after equilibrium is achieved will be Given Kr water 2 0 K kg mol 1 R 0 08 dm atmk mol 1 1 14 Frictionless piston aq ethylene glycol 2 0 57 3 2 18 4 4 36

3 CH CH CH CH CH C CH CH CH 4 CH CH CH CH CH CH C CH CH CH The hardness of a water sample containing 10 M MgSO expressed as CaCO equivalents in pr is molar mass of CaCO is 100 08 g mol 2 75 1 50 Which 3 90 4 100

Solubility of calcium phosphate molecular mass M in water is W g per 100mL at 20 C its solubility product at 25 C will be approximately AAJ KA TOPPER

In which of the following reaction the Kolbe s electrolysis product is Incorrectly mentioned 1 2 3 KOOC COOK 4 co COOK COOK COOK Electrolysis COOK Electroly Electrolys

A ball is projected at an angle of 45 so as to cross a wall at a distance from the point of projection It falls at a distance b on the other side of the wall If h is the height of the wall then 1 h a 2 2 h b 2 3 h 4 h Tab a b ab a b For 1 M 2 A 3 M 4 N 142 The a ve 1 t

164 If wavelength of an electron in the 2nd orbit of hydrogen is x then circumference of the 5th orbit of the same species will be 1 25 x 2 12 5 x 4 x 35 x Oxidation electrode potential of chlorine electrode is maximum

1 14 a Ar 3d 0 4s 4p c Ar 3d 4s 4p Which of the following electronic configurations corresponds to the element with the highest electron affinity 10 Submit 30 b Ar 3d d Ar 3d 04s 4p 4s 4p

1 A B 07 2 A8B6O7 3 AgBgO7 A6B8O6 2 What happens when 2 butyne reacts with H in presence of Nickel Boride or Lindlar s catalyst Pd CaCO3 PbO CH C CH 11 CH C CH 1 2 CH C H 11 H C CH 0000 17 3 CH CH CH CH 4 CH CH IT TC 10 COL CH CH

3 34 2 g 4 136 8 g 8g of NaOH is dissolved in 18g of H O Mole fraction of NaOH in solution and molality in mol kg of the solutions respectively are JEE Main Online 2019 1 0 167 11 11 4 0 167 22 20 2 0 2 22 20 3 0 2 11 11

3 p nitrophenol p methylphenol p methoxyphenol 4 p methoxyphenol p methylphenol p nitrophenol 87 Consider the following compounds CH COCI ii ON O COCI m H C iv OHC The correct decreasing order of their reactivity towards hydrolysis is 1 i ii iii iv 2 iv ii i iii COCI COCI 3 ii iv i iii 4 ii iv

1 13 6 6 8 8 4 eV 2 13 6 10 2 3 4 e 3 13 6 40 8 eV 4 13 6 3 4 A sample of milk splits after 60 min at 300 K and after 40 min at 400 K when the population of lactobacillus acidophilus in it doubles The activation energy in kJ mol for this process is closest to Given R 8 3J mol K In 0 4 e 4 0 1 39 8 2 19 9 3 3 98 4 7 96

If the ionic radii of K and F are about 1 34 each then the expected values of atomic radii of K and F sho be respectively A 2 31 and 1 34 B 2 31 and 0 64 C 0 64 and 2 31 D 1 34 and 1 34

Za dustX CHCY 70 Consider the following reaction Phenol product z is 1 benzaldehyde 2 benzoic acid 71 Coordination number of Ni in Ni C O is 3 4 3 benzene AlkalineKMOZ 1 3 2 6 72 Electrolytic reduction of nitrobenzene in weakly acidic medium gives 4 toluene 4 2 H O the

1 Teflon 2 Natural rubber 75 Gammexane is 1 bromobenzene 2 benzyl chloride 3 chlorobenzene 4 benzene hexachloride 76 An organic compound contains carbon hydrogen and oxygen Its elemental analsysis gave C 38 71 and H 9 67 The empirical formula of the compound would be 1 CHO 2 CH 0 3 CH 0 3 styrene 4 Nylon 6 6 4 CH 0

Consider the following equations 2Fe H O xA yB in basic medium 2MnO4 6H 5H O x C y D z E in acidic medium The sum of the x y x y and z Ometric coefficients products A B C D and E

8 The major product during hydroboration oxidation of 1 methylcyclopentene is CH CH CH 1 2 9 For the reaction N 3H 2NH3 CH OH 3 AAJ KA TOPPER OH

What is the Keg of the following reaction NaCN r t 0 17 Cl b 017 CN AG 0 010 kJ mol c 17 d 0 01

A buffer solution is made by mixing a weak acid HA K 10 6 with its salt NaA in equal amounts What should be the amount of acid or salt that should be added to make 90 ml of buffer solution of buffer capacity 0 1 1 10 milli moles 2 22 milli moles 3 9 milli moles 4 11 milli moles

The value of DH for the reaction below is 128 1 kl CH OH 1 CO g 2H g How many k of heat are consumed when 5 10 g of CO is formed as shown in the equation Select one O a 62 0 X Ob 162 O c 0 182 O d 23 3 O e 8 31

85 Which chloro derivative of benzene among the following would undergo hydrolysis most readily with aqueous sodium hydroxide to furnish the corresponding hydroxyl derivative NO 2 0 N 3 Me N CI 4 C H CI

The correct increasing order of basic strength for the following compounds is NH NH NH 1 3 1 2 NO CH 2 3 2 1 3 2 1 3 4 2 3 1

certain weak acid has a dissociation constant 0 x 104 The equilibrium constant for its reaction ith a strong base is A 1 0 x 10 4 B C 10 1 0 x 101 Your Answer 1 x 10 0 Correct Answer

A compound X upon reaction with H O produces a colorless gas Y with rotton fish smell Gas Y is absorbed in a solution of CuSO4 to give Cua P as one of the products Predict the compound X 1 CazP 2 NH CL 3 As2O3 4 Ca3 PO4 2 124 2 3 4 128 WE 1 2 3

Be sure to answer all parts Click in the answer box to activate each palette Write the balanced equation and solubility product expression for the solubility equilibrium of Mn3 PO4 2 Include physical states and use correct subscripts and superscripts Ksp expression

Fe e Fe EF 0 77V 2 0 30 V 1 0 057 V 3 0 30 V 4 0 057 V 17 Approximate atomic weight of an element is 26 89 If its equivalent weight is 8 9 the exact atomic weight of element would be 1 26 89 2 8 9 3 17 8 4 26 7

5 20 When 1L of CO2 is heated with graphite the volume of the gases collected is 1 8L What will be the number of moles of CO produced at STP Final Results 0 0 0357

AAJ KA TOPPER k 1 72Kkemol a freezing point depression of 2K is observed The van t Hoff

4 NH NH NH 3 NH NH NH Which of the following on heating with aqueous KOH produces acetaldehyde 1 CH CH CI 2 CH CICH CI 3 CH CHCI 4 CH COCI During extraction of silver from cyanide process which of the following is formed 1 Na Ag CN 2 Na Ag CN 3 Na Ag CN 4 None of these

1 1 2 0 3 1 4 2 The alkali metals dissolve in ammonia to give a deep blue solution which is conducting in nature M x y NH M NH 2 c NH 1 The blue colour is due to ammoniated electron 2 The solution is paramagnetic 3 The blue colour changes to brown on standing 4 In concentrated solution blue colour changes to bronze and becomes diamagnetic

2 Describe briefly what happens in an unmagnetised ferromagnetic substance when it is magnetised by means of an externally applied magnetic field Provide a brief discussion of the hysteresis loop as part of your description 4 Points th Na 1 and 2

a more b less c medium d high 5 In AAS high concentrations of gaseous atoms cause of absorption lines a narrowing b broadening c resonance In AAS is obeyed over a wide range of concentrations DL c Beer s law 7 d sputtering d Bouguer s law

and 6 Two buffers X the salt NaA Both the buffers are 0 50 Min respectively are prepared from acid HA 2 HA What would be the pH of the solution obtained by mixing equal volumes of the two buffers K 1 0 105 A 4 7033 C 6 7033 B 5 7033 D 8 7033

9 0 IV Distillation of calcium benzoate 1 I and IV 2 I and II 3 I and III 4 III and IV The relative abundance of two isotopes of an element with atomic weight 85 and 87 is 75 and 25 respectively Then calculate the average atomic weight of element 1 86 0 2 85 5 3 75 5 4 40 0 Which given compound can be reduced with zinc amalgum and hydrochloric acid

22 Which of the following compound does undergo aldol condensation 1 HCHO CH I 2 CH C CHO 1 CH 3 CC1 CHO OF AUG

CHEMISTRY For a photochemical reaction AB 1 0x105 mole of B were formed on absorbing 1 2x10 quant each of 2 360 nm The quantum efficiency is given by 1 0 50 2 1 3 0 1 4 0 2

a gratings b prisms c filters 6 Spectral interference is much when monochromators are used a less c very high d low b high Q 2 State whether true or false Flomo omiccion is primarily used for quantitative determination of alkali and alkal

Which one of the following statements is incorrect in relation to ionisation enthalpy A B lonisation enthalpy increases for each successive electron D The greater increase in ionisation enthalpy is experienced on removal of electron from core noble gas configuration End of valence electrons C is marked by a big jump in ionisation enthalpy Removal of electron from orbitals bearing lower n value is easier than from an orbital having

An inorganic salt is lemon yellow in colour It becomes orange in colour like methyl orange when it is acidic and again becomes yellow when it is alkaline The inorganic salt will be Question Type Single Correct Type 1 Copper nitrate 2 Ferric chloride 3 Potassium chromate