Physical Chemistry Questions

Find the pH of the equivalence point and the volume mL of 0 0639 M KOH needed to reach the equivalence point in the titration of 23 4 mL of 0 0390 M HNO2 Volume mL KOH pH

42 At 27 C latent heat of fusion of a compound is 2930 J mol Entropy change is 1 9 77 J mol K 3 9 07 J mol K 2 10 77 J mol K 4 0 977 J mol K

Potassium crystallizes in BCC with unit cell edge length of 500 pm Identify correct statement s about this solid Given N 6 10 Shortest distance between two potassium atoms is 4 33 The number of next nearest neighbours of each potassium atoms are 8 Shortest distance between two potassium atoms is 3 54 The density of this solid is 10 4 gm cm K 39

1 A mixture of 2 3 g formic acid and 4 5 g oxalic acid is treated with conc H SO4 The evolved gaseous mixture is passed through KOH pellets Weight in g of the remaining product at STP will be a 1 4 c 2 8 b 3 0 d 4 4 2018 6

b 10 Which pair will show common ion effect a BaCl Ba NO3 2 c NH OH NH4Cl c 10 MPPMT b NaCl HCI d AgCN KCN If s and Kp are respectively solubility and solubility product

of a hypothetical salt MX is 150 kJmol and for MX2 it is 600 kJmol The enthalpy of disproportionation is 100 x kJmol The value of x is 1 3

Thermodynamics 23 The heat of neutralization of LiOH and HCI at 25 C in 34 868 kJ mol The heat of ionisation of LiOH will be 1 44 674 kJ 2 22 232 kJ 3 32 684 kJ

of Mg OH will begin from 3 3 4 7 OH precipitation M Mg2 solution 1 9 2 5

1 pH of 10 8 M NaOH is a 8 0 b 6 0 c 6 98 d 2 Milliequivalent of Ba OH 2 present in 100 mL solution to have pH 13 is a 10 2 d 0 01 c 0 1 temperature under high pressure 10 10 b 10 At a to h

2 Equivalent resonating structures result in higher resonance energy 3 Resonating structures represent hypothetical molecules having no real existence 4 Resonating structures are less stable than the resonance hybrid In some solutions the concentration of H O remains constant even when small amounts of strong acid or strong base are added to them These solutions are known as 1 Ideal solutions 2 Colloidal solutions 3 True solutions 4 Buffer solutions

The heats of combustion of yellow P and red P are 9 91kJ and 8 78kJ respectively The heat of transition of yellow to red phosphorus is 1 18 69 kJ 2 1 13 kJ 3 18 69 kJ 4 1 13 kJ

1 dox NEET VOL 11 In the reaction K O KO 1 O acts as an oxidising agent 2 Both K and O are oxidised 2 3 O is oxidised with K is reduced 4 K acts as an oxidising agent 12 Cr O X Cr H O oxidised product of X X in the above reaction cannot be 2 1 C O 2 Fe 3 SO 4 S

The heat of combustion of a reaction does not depend on a Physical state of the substance b Temperature at which combustion is carried out c Amount of oxygen present d Whether the combustion is carried out

Q 1 Solve the following multiple choice questions 1 Varnish is used to give A Transparent finish B Red colour finish C Opaque finish D Fire resistant finish 2 Thinners are added to paint to A Improving drying quality B Reduce the cost C Reduce the consistency D Provide water proofness Record 3 The paint is a mechanical dispersion mixture of one or more A Resin B Polymer C Pigment D Monomer O istr screenshot in a vehic

How many times more soluble is AgCl when added to a solution of NaCN A colorless complex ion Ag CN 2 results from this addition Ksp for AgCl is 1 8 x 10 10 and Kf for Ag CN 2 is 1 0 x 1021 A 8 1 x 10 7 B 1 0 x 1021 C 1 8 x 10 10 D 1 8 x 1011 O A B A

The EMF of a cell corresponding to the reaction Zn s 2H aq Zn 0 1M H g latm is 0 28 volt at 25 C The pH of the solution at the hydrogen electrode AAJ KA TOPPER E 0 76 volt E 0 1 2 30 2 7 8 3 9 2 Arrange the following in correct order of Lewis acidity BF BCL BBr 4 8 30

A metal A exists in the bcc structure having uncovered length between the atoms along the edge in an unit cell equal to 1 2 If molar mass of the metal is 307 2 gm mole then calculate density of the crystal in gm ml Use NA 6 x 1023 and 3 1 7

a Identify the correct statement regarding entropy 1 At absolute zero of temperature the entropy of all crystalline substances is taken to be zero 2 At absolute zero of temperature the entropy of a perfectly crystalline substance is ve 3 At absolute zero of temperature entropy of a perfectly crystalline substance is taken to be zero 4 At 0 C the entropy of a perfectly crystalline substance is taken to be zero

A solution of acetone in ethanol 1 Obeys Raoult s law 2 Shows a negative deviation from Raoult s law 3 Shows a positive deviation from Raoult s law 4 Behaves like a near ideal solution HO OH incomplete

Use the data provided to determine the rate law including the value of k of the following reaction 2 NO g O2 g 2 NO2 g Rate 1 7x103 M s NO 0 1 Rate 3 1 105 M s NO 0 1 Rate 57 M2s NO 0 Rate 3 8 M 1 2 1 NO 0 2 Rate 9 4 103 M2s NO 0 1 Rate 57 M s NO 0 NO M 0 030 0 030 0 060 02 M 0 0055 0 0110 0 0055 Initial Rate M 15 1 0 00855 0 0171 0 0342

45 When 1 mol of gas is heated at constant volume temperature is raised from 298 to 308 K Hea supplied to the gas is 500 J Then which statement is correct 1 q AU 500 J W 0 2 qAU 500 J w 0 3 q w 500 J AU 0 4 AU 0 q w 500 J

6 The equation for the formation of lithium bromide is Li Br LiBr If 5 0 grams of each reactant are used Which substance is the limiting reagent F Lithium G Bromine H Lithium bromide 1 There is no limiting reagent

3 If sulfur has two isotopes one with a mass of 32 and the other with a mass of 35 and the average mass is 32 1 if you pulled out a single sulfur atom would it have a mass of 32 1 Why or why not

An equilibrium mixture at 300 K contains N O and NO at 0 28 and 1 1 atmosphere respectively If the volume of container is doubled calculate the new equilibrium pressure of two gases Roorkee 1991 P 0 045 P 0 095 atm Pro 064 atm

2 3 grams of a mixture of NO2 and N O4 have a pressure of 0 82 atm at temperature T K and volume V litres calculate PNO2 Assume V T 1 300 that all the NO2 was converted into N O4 If A 0 52 atm B 0 38 atm C 0 19 atm D 0 41 atm

4 Varnish is a homogeneous colloidal dispersion solution of in oil or thinne or in both apreenshot A Pigment B Resin C Salt D Gypsum 5 The material which are used to prevent the flow of heat are known as A Insulators B Conductors C Semiconductor D Paints cty

The following data is obtained during the first order thermal decomposition of 2 A g B g C B g at constant volume and temperature S No Time At the end of 10 minutes After completion 1 The rate constant in min is a 0 0693 c 0 00693 1 2 b 6 93 d 69 3 Total pressure in Pascal 300 200 KCET 2010

The IUPAC name of the compound ur is 1 3 Keto 2 methylhex 4 enal 3 5 Methyl 4 oxohex 2 en 5 al Statement 1 For adsorption AG AH AS all have negative values 2 5 Formylhex 2 en 3 one 4 3 Keto 2 methylhex 5 enal

0 Which postulate of the kinetic molecular theory BEST explains why gases can be compressed F Gases are in constant random motion G Gas particles move in a straight line until they collide with other matter H There is empty space between gas particles 3 There is no force of attraction between gas particles

Which of the following are correct Ksp of Fe OH 3 in aqueous solution is 3 8 x 10 38 at 298K The concentration of Fe will increase when H ion concentration decreases In a mixture of NH4Cl and NH4OH in water a further amount of NH4Cl is added The pH of the mixture will decreases An aqueous solution of each of the following salts NH4l Cr NO3 3 9H2O KCN will be basic basic acidic respectively From separate solutions of four sodium salts NaW Nax NaY and NaZ had pH 7 0 9 0 10 0 and 11 0 respectively when each solution was 0 1M the strongest acid is HW

The equilibrium constant for a reaction A B C D is 1x10 at 298K and is 2 at 273 K The chemical process resulting in the formation of C and D is 2 Endothermic 3 Unpredictable 1 Exothermic 4 There is no relationship between AH and K The most suitable method of separation of 1 1 mixture of ortho and para nitrophenol is 2 Crystallication 1 Sublimation 2 Chromatography 4 Steam distillation

3 A mixture of methane and ethene in a molar ratio ofx y has an average molecular mass of 20u The mean molar mass when they are mixed in the molar ratio y x will be 2 25 u 3 24 u 1 20 u 4 15 u

For the reaction 3A 5B 2C 4D which reaction rate relationship is true a 4 B SA D 4 At O 3 Ob 4 B 4 A 5 3 Oc 4 A 4 B At O c At D A D 4 A A 3 At d 4 D A C 2 A B

Acetic anhydride is prepared in the laboratory by heating sodium acetate with 1 Ethyl chloride 2 Acetyl chloride 3 Conc H SO 4 Zinc dust An unknown alcohol is treated with the Lucas reagent to determine whether the alcohol is primary secondary or tertiary Which alcohol reacts fastest and by what mechanism 1 Secondary alcohol by S 2 2 Tertiary alcohol by S 2 4 Tertiary alcohol by S 1 3 Secondary alcohol by S 1

Board Competitive Exams 44 Change in enthalpy for reaction 2H O 2H O 1 O g if heat of formation of H O and H O l are 188 and 286 kJ mol respectively is 1 196 kJ mol 2 196 kJ mol 3 948 kJ mol 049

In order to oxidise a mixture of one mole of each of FeC O4 Fe C O4 3 FeSO4 and Fe SO4 3 in acidic medium the number of moles of KMnO4 required is JEE Main 2019 8 April Shift 1 c 3 d 1 5 a 2 b 1

Dependence of rate constant of a reaction is given by Arrhenius equation k A e RT but originally it s derived from it s differential equation Reactions A B C D follows following rate law rate k A 1 2 B 1 2 Starting with initial conc of one mole of A and B each what is the time taken for amount of A of become 0 25 mole Given k 2 31 10 3 sec 1 300 sec 600 sec O900 sec

The system N O 2 NO maintained in a closed vessel at 60 C a pressure of 5 atm has an average i e observed molecular weight of 69 calculate K At what pressure at the same temperature would the observed molecular weight be 230 3

Consider the following reaction where K 2 90 10 at 1150 K 280 g 250 g O g A reaction mixture was found to contain 3 61 10 moles of SO g 1 83 102 moles of SO g and 4 06x102 moles of O g in a 1 00 liter contain Is the reaction at equilibrium If not what direction must it run in order to reach equilibrium The reaction quotient Qe equals The reaction A must run in the forward direction to reach equilibrium B must run in the reverse direction to reach equilibrium Gis st aqulibein

primary secondary or tertiary Which alcohol reacts fastest and by what mechanism 1 Secondary alcohol by S 2 2 Tertiary alcohol by S 2 3 Secondary alcohol by S 1 4 Tertiary alcohol by S 1 30 mL of 0 2N BaCl is mixed with 40 mL of 0 3 N AL SO How many g of BaSO are forme 1 0 10 g 2 0 60 g 3 0 90 g 4 0 70 g 1 mole each of AgNO CuSO and AICI is electrolysed Then ratio of number of Farad

To assess the stoichiometry of a reaction one must use the Select the correct answer below Ounbalanced chemical equation O balanced chemical equation O masses of the substances O volumes of the substances

A compressed cylinder of gas contains 1 50 10 g of N gas at a pressure of 2 0 x 107 Pa and a temperature of 17 1 C What volume of gas has been released into the atmosphere if the final pressure in the cylinder is 1 80 x 105 Pa Assume ideal behaviour and that the gas temp is unchanged 1 1260 L 2 126 L 3 12600 L 4 45 L

When 5 litres of a gas mixture of methane a propane is perfectly combusted at 0 C ar 1 atmosphere 16 litre of oxygen at the san temperature and pressure is consumed TI amount of heat released from this combustion in AH comb CH 890 kJ mot AH comb C h 2220 kJ mol is 1 32 3 317 2 38 4 477

Choose the incorrect option regarding following complex is K Pt Cl cl x O z x Bond length Odsp hybridisation O O S of Pt 2 O C C bond length in this complex is less than individual CH CH CH CH M

The decomposition of H O can be followed by titration with KMnO and is found to be a first order reaction The rate constant is 4 5 x 10 2 In an experiment the initial titre value was 25 ml The titre value will be 5 ml after a lapse of

1 In the reaction S 3 2 O SO 2x kcal and SO y kcal the heat of SO 1 2 0 formation of SO is 1 2x y 2 x y 3 x y 4 y 2x 2 At 27 C latent heat of fusion of a compound is

Calculate the ratio of solubility of AgCl in 0 1M AgNO and in pure water Given K of AgCl 1 8 x 10 0 1 1 34 x 10 5 M 3 2 x 10 8 M 2 1 34 x 10 4 M 4 3 x 10 6 M

F then calculate the value of Z for the vapours One litre gas at 400 K and 300 atm pressure is compressed to a pressure of 600 atm and 200 K The compressibility factor is changed from 1 2 to 1 6 respectively Calculate the final volume of the gas

1 25 2 50 3 75 4 100 1 In the synthesis of ammonia by Haber s process if 60 moles of ammonia is obtained in one hour then the rate of disappearance of nitrogen is 1 30 mo min 2 6 mol min 2 3 0 5 mol min 4 60 mol min The solubility product of Ag Cro is 32x10 What is the concentration of Cro ions in that solution

1 The rate law for the reaction below is given by the expression K A B A B Product If the concentration of B is increased from 0 1 to 0 3 mole keeping the value of A at 0 1 m the rate constant will be 1 3K 2 9K 3 K 3 4 K