General Questions and Answers

The Haber Process A Study in Chemical Equilibrium Learning Goal I can analyze the optimal conditions for a specific chemical process related to the principles of equilibrium that takes place in natu A See Answer Q What are some real life examples of polyaniline synthesis for how polyaniline works as a sensor at the molecular level How does this relate to important real life contexts A See Answer Q MgO vs MgCl2 which has a higher melting point and why show proof A See Answer Q Discuss why the temperature remains constant while a pure liquid freezes but the temperature drops

Then Y is given by 1 A B A plate has a length 1 10 0 25 cm 2 AB 3 AB 4 A B s 5 0 1 cm and breadth 2 0 01 cm Then the area of the plate is 2 10 0 01 cm 3 10 0 001 cm 4 10 1 cm

One mol of H SO is completely neutralised with 2 mole of NaOH in dilute solutions The amount of evolved during the process is 1 57 2 kJ HA 9 57 2kJinnerbobns 2 2 eyswis 3 13 7 kCal oge 4 114 4 kJ

InH In H K 105 if 20 ml of 0 2M H SO solution is titrated with 0 1M KOH solution How much volume of base is consumed by the time 66 6 of the indicator is ionized Ka Ka of H SO are 10 and 10 respectively

Density of 2 03 M aqueous solution of acetic acid is 1 017 g ml molecular mass of acetic acid is 60 Calculate the molality of solution 1 2 27 2 1 27 3 3 27 4 4 27 A molar solution is one that contains one mole of solute in 1 1000 g of the solvent 3 1000 g of the solution 2 one litre of the solution 4 22 4 litres of the solution

Identify X in the equation FeCl3 SO2 H O A H S C H SO4 given below FeCl HCI X 8 and 2 B SO3 D H SO3

In which mode of expression the concentration of the solution remains dependent upon temperature Mole fraction Molality w w hr W V

and 74 5 ppm of potassium chloride is 1 8 2 4 3 3 4 2 A 5 0 cm solution of H O liberates 0 508 g of 1 from an acidified Kl solution The strength of H O solut 2 in terms of volume strength at STP is 1 2 24 V 2 1 12 V 3 4 48 V 4 8 96 V

ansion of an ideal gas under isothermal adiabatic conditions are as shown in the figure and P correct a AS isothermal AS adiabatic b T TB c Wisothermal Wad d T A PA VA TA adiah AB Isothermal expansion AC Adiabatic expansion Which of the following options is not B P V TB C Po Vo Tc V

Consider the following statements 1 Element with atomic number 43 belong to d block element II 64Gd is present in group 3 III Se has two unpaired in p orbital The correct statement s is are Only III Only 1 II Only 1 III 1 II III

Assuming ideal gas behaviour and only bimolecular collisions to be occuring which of the following gases will have longest mean free path under identical concentrations 1 H 3 CL 2 N 4 F

Carbon and oxygen combine to form two oxides carbon monoxide and carbon dioxide in which the ratio of the masses of carbon and oxygen is respectively 12 16 and 12 32 These figures illustrate the a law of multiple proportions c law of conservation of mass b law of reciprocal proportions d law of constant proportions

Determine the number of water molecules necessary to balance the following chemical equation before the H s would be balanced Cr O72 aq 2Cl aq 2Cr aq Cl g H O 1 A 3 B 5 C 7 D 14 A OB OC OD

In a fuel cell methanol is used as fuel and oxygen gas is used as an oxidizer The reaction is CH3OH 1 O g CO g 2 H O 1 2 At 298 K standard Gibb s energies of formation for CH3OH 1 H O 1 and CO g are 166 2 237 2 and 394 4 kJ mol respectively If standard enthalpy of combustion of methanol is 726 kJ mol 1 then percentage efficiency of the fuel cell will be Report the answer to nearest integer

29 The packing efficiency unit cell shown below is a 39 27 c 74 05 BB L b 68 02 d 78 54 ooked

A helium filled balloon can lift a load of 211 kg this includes mass of empty balloon Given that density of air is 1 29 kg m and density of helium is 0 179 kg m determine the minimum volume of helium needed to fill in such balloon Hint Helium has its own mass and volume of displaced air is equal to the volume of helium Select one O a 164 m O b 144 m Oc 190 m O d Impossible to answer since mass helium is not given O e 118 m

6 Calculate the mass of benzene that would be required to produce a current of one ampere for three hours from following data 0 6CO 3H O 15 C H 2 1 0 386g 3 0 291g 2 0 222g 4 0 333g

photoelectric tric em 1 6 10 10 J 2 1 2 10 18 J 3 3 10 19 J 4 6 10 19 J A certain metal when irradiated with light v 3 2 10 6 Hz emits photo electrons with twice kinetic energy as did photo electrons when the same metal is irradiated by light v 2 0 10 6 Hz Calculate v of electron 1 1 2 10 4 Hz 2 8 x 10 5 Hz 24016 H MY 1 x 10 2 Hz

Question The 1st 2nd and the 3rd ionization enthalpies 7 72 and 13 of four atoms with atomic numbers n n 1 n 2 and 3 where 10 are tabulated below What is the value of n Atomic Number n n 1 n 2 Ionization Enthalpy kJ mol 1681 2081 469 12 3374 3952 4562 13 6050 6122 6910

R 8 314J K 1 mol 1 72 2 166 3 150 13 In the following reaction xA yB d A log10 log10 d B dt 2 C H and C Hg 3 N O4 and NO 4 C H and C H A and B respectively can be 1 n Butane and Iso butane 4 59 0 3010

6 Water at 20 C flows at 5 m s past a 2 m wide sharp flat plate a Estimate the turbulent boundary layer thickness at x 1 2 m b If the total drag on both sides of the plate is 310 N estimate the length of the plate Use 1 7th power law for velocity profile

C 34 Calculate the half life of the first order reaction C H4O g CH g CO g If the initial pressure of C H4O g is 80 mm and the total pressure at the end of 20 min is 120 mm a 40 min c 20 min b 120 min d 80 min we samples are 0 1 and 0 8 s 41

3 equal in both ca Which of the following solutions will exactly oxidize 25 mL of an acid solution of 0 1 M iron II oxala 2 25 mL of 0 2 M KMnO4 1 25 mL of 0 1 M KMnO4 3 25 mL of 0 6 M KMnO4 4 15 mL of 0 1 M KMnO4 le of MnO ion in acidic medium is

moles H O is 0 50 On reaction with AgNO3 this solution will form assuming no change in degree of Relative decrease in vapour pressure of an aqueous solution containing 2 moles Cu NH3 3CI CI in 3 ionisation of substance on adding AgNO3 A 1 mol AgCl B 0 25 mol AgCl C 0 5 mol AgCl D 0 40 mol AgCl

3 8 1 The ionisation energy of H atom in the gr state is x kJ The energy required for an ele to jump from 2nd to 3rd orbit will be 1 x 6 3 7 2x MKS sha 2 5 4 5x B6 A

Method of preparation of colloidal solution is given below How many solutions are negative reduction noitula 1 2AuCl3 3HCHO 3H O 1916w 2 Sol of starch pienel 3 Fe OH 3 FeCl3 Colloidal sol B 4 AgNO3 Kl excess Colloidal sol 8 5 Basic dye stuffs no s 6 Fe OH 3 NaOH 7 Acid dyes colloidal sol Colloidal sol odernongo ng to

If 72 5 g of gold s 25 41 J mol C at 64 2 C is added to 100 0 g of water s 75 3 J mol C at 23 0 C what is the final temperature of the water assuming no energy is lost to the container Au 196 97 g mol H O 18 g mol 31 1 1 C

The equilibrium constant K at 27 C for homogeneous gaseous reaction is 108 The standard free energy change AG for the reaction using R 2 Cal K mol is 1 11 05 kcal 3 4 145 kcal 2 1 8 kcal 4 None of these

In Vander Waal equation a and b respectively tells us about 1 Attraction force and repulsive force 2 Volume and attraction force between molecules 3 Size and force of attraction between molecules 4 Attractive force and volume of molecules

Unknown salt A K Cr O conc H SO Reddish brown fumes Which is the correct statement regarding the above observation 1 It confirms the presence of Cl ion 2 It confirms the presence of Brion 3 It confirms the presence of both 4 It neither confirms Cl nor Br unless it is passed through NaOH solution

3 Oxidised only 4 Reduced only The number of moles of KMnO reduced by one mole of KI in alkaline medium is 16 1 one 3 five 01xx 1x 1 4 2 two In the balanced chemical reaction 4 one fifith AIPMT 200 277 2

Arrange the following in the order of increasing mass atomic mass O 16 Cu 63 N 14 I one atom of oxygen II one atom of nitrogen III 1 10 10 mole of oxygen IV 1 10 10 mole of copper II I III IV a c III II IV I b I II III IV d IV II III I

1 4 5 g 2 6 3 g 125 mL of 63 w v H C O 2H O solution is made to react with 125 mL of a 40 w v NaOH solution The resulting solution is ignoring hydrolysis of ions neutral 2 acidic 3 strongly acidic 4 alkaline 125 ml of 63 w v H C 0 2H O solution is made to react with 125 mL of a 40 w v NaOH solution Th

The rate of the reaction 2A B given by the rate expression rate k A 1 5 B 0 5 If A is 2 molar and B is 100 molar then the NCERT Pg 1027 order of reaction will be 1 2 2 0 5 3 1 5 C

Sea water is found to contain 5 85 NaCl and 9 50 MgCl2 by weight of solution Calculate its normal boiling point assuming 80 ionisation for NaCl and 50 ionisation of MgCl2 K H2O 0 51 kgmol 1 K To 101 9 C BYT 102 3 C C Tb 108 5 C D Tb 110 3 C

Consider the equilibrium of magnesium fluoride MgF s in water MgF s Mg2 aq 2F aq What is the effect of adding strong base sodium hydroxide i e increasing the pH of solution O The F will be protonated resulting in more MgF s dissolving O The base will have no effect on the magnesium fluoride equilibrium O More MgF s will be formed thus reducing Mg2 and F concentrations in solution O Magnesium hydride MgF s will precipitate O Magnesium hydroxide Mg OH s will precipitate

36 The major products A and B in the following reactions are A 1 A 2 A 3 A CN 4 A Peroxide Heat CN CN te CN te CN and B A and B and B and B B JEE Main 2020 CN CN CN Medical I Divisions

7 The molality of solution containing 15 20g of urea molar mass 60 dissolved in 150g o water is 8 1 1 689 mol kg 2 0 1689 mol kg 3 0 5922 mol kg 4 0 2533mol kg Dipole induced dipole interaction are present in which of the following pairs 1 H O and alcohol 2 Cl and CCI

The boiling point of C6H6 CH3OH C6H5NH and C6H5NO2 are 80 C 65 C 184 C and 212 C respectively Which will show highest vapour pressure at room temperature Option A B C6H6 CH3OH Rate thi

Tollowing ments a Critical temperature of ammonia is higher than carbon dioxide b Above Boyle point real gases show positive deviation from ideality c At 1 atm pressure boiling point is called standard boiling point The correct statements are a and c only a and b only a b and c b and c only

the initial pressure of N and H mixture in a closed apparatus is 100 atm At equilibrium 20 of the mixture reacts then total pressure at the same temperature would be 1 100 2 90 4 80 3 85

It has been found that gaseous iodine molecu just dissociates into iodine atoms after absorptic of light at wavelengths 4995 A The energy require to dissociate 1 mole of iodine molecules is 1 52 2 kcal mole 3 63 4 kcal mole 2 93 4 kcal mole 4 57 3 kcal mole

57 58 The first and second ionization enthalpies of a metal are 496 and 4560kJ mol respectively How many moles of HCI and H SO respectively will be needed to react completely with 1 mole of the metal hydroxide 2 1 and 2 1 1 and 1 3 2 and 0 5 Among the statamante 1 4 the correct ona am 3 1 and 0 5

or B B 4L of 0 02 M aqueous solution of NaCl was diluted by adding one litre of water The molarity of the resultant solution is a 0 004 c 0 012 b 0 008 d 0 016 On the basis of information given below mark the correct

To measure the amount of iron in a certain type of iron ore an analytical chemist dissolves a 21 00 g sample in strong acid and titrates it to the endpoint with 29 3 mL of 0 4800M potassium permanganate KMnO4 solution The balanced chemical equation for the reaction is 8H aq 5Fe aq MnO4 aq What kind of reaction is this 1 3 2 SFe aq Mn aq 4H 0 1 If you said this was a precipitation reaction enter the chemical formula of the precipitate If you said this was an acid base reaction enter the chemical formula of the reactant that is acting as the base If you said this was a redox reaction enter the chemical symbol of the element that is oxidized Calculate the mass percent of Fe in the sample Be sure your answer has 3 significant digits precipitation acid base redox 0 0 0 X 5 1x30

OU 180 Mark for Review In zinc blende structure Zn ions are present At all the corners of the cube In all the tetrahedral voids In all the octahedral voids In half of the tetrahedral voids h

5 Consider the following reaction N 04 8 2NO g AH 58 kJ For each of the following cases A B the direction in which the equilibrium shifts is A temperature is decreased B pressure is increased by adding N at constant T JEE Main 2020 5 September Shift 1 a A towards product B towards reactant b A towards reactant B no change c A towards reactant B towards product d A towards product B no change

If two liquids A and B form minimum boiling azeotrope at some specific composition then a A B interactions are stronger than those between A A or B B b vapour pressure of solution increases because more number of molecules of liquids A and B can escape from the solution c vapour pressure of solution decreases because less number of molecules of only one of the liquids escape from the solution

B C H O C C H O D CH O A C H O When 1 615 gram anhydrous salt was placed in a moist air its mass was found to be 2 875 gram The percentage amount of elements in anhydrous salt is as follows Zn 40 6 S 19 8 and O 39 6 If complete hydration of a salt is taking place then calculate the number of molecules of water of crystallisation A 2 B 5 C 6 D 7

DDT a pesticide that kills disease carrying mosquitoes is synthesized by the given equation DDT is now banned in the United States because it is a persistent environmental pollutant that only slowly degrades 2 C6H5Cl C HC130 112 6 g mol C14H9Cl H O 4 DDT a What is the theoretical yield of DDT in grams from 72 4 g of chlorobenzene 97 8 b If 68 9 g of DDT are formed in the reaction what is the percent yield of DDT 84 4 g DDT