Physical Chemistry Questions

react how many mol of O could be produced 0 1 8 32 16 Question 32 2 points Hydrogen peroxide reacts to form water and oxygen gas H O aq H O 1 O g If 32 2 g of O are produced from this reaction how grams of H O would also be produced 16 1 g 64 4 g 72 0 g

112ysin 0 3 2v cos 2 vain 0 2 4 v cos0 2 Aplane mirror roatating at an angular of 3 radian s reflects a light beam The angular of the reflected beam is 3 9rad s 4 12rad s velocity 13rad s Two candles initially of equal height h are distance at a distance of a from each other The between each candle and the nearest wall is also a With what speed the shadow of the left side candle will move along the left wall if left side candle burns down in the time and the right side in the time 1 a 1112 4 24 4 1 1 2 a h 11 Your idem vertically shown in midpoin reflectic 21 1 h 4 12 1 3 12 F 3142 1 Following figure shows the multiple reflections of a light ray along a glass PAR 11 1

3 Calculate the excess air coefficient by writing the combustion equation since the dry based exhaust gas components measured by the exhaust emission device of an engine running on gasoline CSH15 are 14 29 CO2 60 637 CO 60 0217 CSH15 0 65 02 60 2029 NO by volume M 29 kg kmol y fast answer pleaseee

E Which buffer system below is best equipped to maintain a pH of 7 0 25 C A 25 mM Tris HCI buffer pKa 8 08 B 50 mM Carbonate buffer pKa 6 37 C 10 mM HEPES buffer pKa 7 55 D 50 mM Phosphate buffer pKa 6 86 E 100 mM Acetate buffer pKa 4 76

210 The threshold frequency vo for a metal is 5 x 1014 s Calculate the kinetic energy of an electron emitted when the metal is irradiated with a radiation of frequency 2 x 10 5 Hz 2 twn experimental phenomena ukish M G groterand II 2

When some NaCl was dissolved in water the freezing point depression was numerically equal to twice the molal depression constant The relative lowering of vapour pressure of the soluon is Assume 100 NaCl aq dissociation A 0 117 C 0 0685 D 0 0089 B 0 034

The degree of hardness of a water sample is found to be 100 ppm 50 of hardness is temporary hardness due to Ca HCO3 2 If weight of slaked lime in mg required to remove completely the temporary hardness in 1 litre of that water sample is x Then the value of X 3 is 10

4F Show with equations and text how you would calculate the pH for seawater S 35 t 25 C that is in equilibrium with calcium carbonate aragonite if the alkalinity of the seawater is 2221 60 micromoles kg

a Please write ODEs to describe this system following the Laws of Mass action There should be 5 equations one for each species present in this system for example d A dt A L u ALC KLA KAL KAB KBA KBLC KALC B L KLB BLC KBL Y Inactivated receptor Y Activated receptor

10 The time require for 10 completion of a first order reaction at 298K is equal to that required for its 25 completion at 308K if the value of A is 4x1010 sec 1 1 5 1 5 2 5 calculate k at 318K Ea

1 The energy of an electron in the second and third Bohr s orbits of a hydrogen atom are 5 41 x 10 erg and 2 41 x10 2 erg respectively The wavelength of emitted radiation when the electron drops from the third to the second orbit is x x 107 m The value of x is Use h 6 63 x 1034 Js 12 2 g of CH g at a certain temperature and pressure condition occupies 11 2 L If the pressure of the gas is

Using transition state theory estimate the rate constant for a reaction where the two reactants are diatomics and the transition state is non linear Assume hard sphere collision limit and that the reaction is occurring at room temp Also assume that the vibrational levels of all species are widely spaced and there is no degeneracy in the electronic states of the system

7 92 U235 nucleus absorbs a neutron and disintegrates into 54 Xe139 38 Sr94 and x What will be the product x 1 3 neutrons 2 2 neutrons 3 2 a particles 4 2 B particles

If an element at wt 50 crystallizes in fcc lattice with a 0 50 nm What is the density of unit cell if it contains 0 25 Schottky defects use N 6 10 A 4 0 g cc B 2 66 g cc C 7 06 g cc D 0 66 g cc

The thermal dissociation equilibrium of CaC CaCO3 s CaO s CO g For this equilibrium the correct statement s is are A AH is dependent on T B K is independent of the initial amount of CaCO3 C K is dependent on the pressure of CO2 at a given T D AH is independent of the catalyst if any mperature

3 2 particles 8 The half life of C 14 is 5600 years A sample of freshly cut wood from a tree contains 10 mg of C 14 The amount left in the sample after 50000 years is a x 100 The value of a x x 100 is 11 2 2 4 4 IS 3 3

The Arrhenius activation energy for the following reaction is 15 5 kJ mol What is the value of AH The reaction is H g Br g HBr g Br g A 1 13 kJ mol B 7 19 J mol C 7 19 kJ mol D 1 13 kJ mol

EXAMP The activity of 1 g of radium is found to be 0 5 curie Calculate the half life period of radium and the time required for the decay of 2 g of radium to give 0 25 g of radium atomic mass of radium 226 1023

1 The vapour pressure of pure benzene at a certain temperature is 640 mm Hg A non volati non electrolyte solid weighing 2 175 g is added to 39 0 g of benzene The vapour pressure of the solution 600 mm Hg What is the molecular weight of the solid substance in terms of atomic mass unit

Different alternating voltages are given below In which case the peak value and rms value are same a Vol V c V b 0 Vol d A M V Vol TV V VI 1 c only 2 d only

An electrolyte solution of XY with molality of 8 545 x 10 3 mol kg was electrolyzed in a Hittorf cell The mass of metal X molar mass and equivalent weight 112 4 deposited at the cathode was 0 01462g A solution weighing 113 25 g was withdrawn from the anode compartment and was found to contain 0 3321g of XY Calculate the transport numbers of the X and Y ions Molar mass and equivalent weight of electrolyte is 366 2

To make negative sols Agl which of the following mixing is favoured 10 ml 0 1 M AgNO3 10 ml 0 1 M KI 10 ml 0 1 M AgNO3 12 ml 0 1 M KI 12 ml 0 1 M AgNO3 8 ml 0 1 M KI X All of these

A reaction is non spontaneous when placed in ice water but spontaneous when placed in a hot bath What can you deduce regarding the signs for AH and AS for this reaction A Both are positive B AH is positive and AS is negative C AH is negative and AS is positive D Both are negative

A mixture of two immiscible liquids nitrobenzene and wat er boiling at 97 C has a partial vapor pressure of water 73 3 mm and that of nitrobenzene 27 mm The ratio of the we ights of water to nitrobenzene in the distillate is

At 40 oC the vapor pressure of n pentane n C5H12 is 873 mm and the vapor pressure ofn heptane n C7H16 is 92 mm Use Raoult s Law to calculate the vapor pressure at 40 oC of a 3 1 molar mixture of n pentane and n heptane Do the same for a mixture containing 50 g of each component

NA 2 A sample of H atoms having electrons in the ground state is exposed to high energy rays of quantum energy 13 3875 eV The H atoms absorb the energy and get excited When the electron drops from excited state to the ground state how many lines are seen in the emission spectrum of hydrogen

ZnSO4 CuSO4 IM IM The potential of the cell Zn was reported by Buckbee Surdzial and Metz as E 1 1028 0 641 x 10 3 T 0 72 x 10 5 T2 where T is the temperature in degree celsius Calculate AS for the cell reaction at 25 C a 45 32 c 25 43 Cu b 34 52 d 54 23

The decomposition of N O in chloroform was followed by measuring the volume of O gas evolved 2N O CCI 2N O CCL O g The maximum volume of O gas obtained was 100 cm In 500 minutes 90cm of 0 was evolved The first order rate constant in min for the disappearance of N 0 i A 2 303 500 2 303 100 B log C 500 90 2 303 90 500 100 log D 100 10 500

2 A sample of H atoms having electrons in the ground state is exposed to high energy rays of quantum energy 13 3875 eV The H atoms absorb the energy and get excited When the electron drops from excited state to the ground state how many lines are seen in the emission spectrum of hydrogen

V An 7 Values of x y and z respectively for the balanced redox reaction are P s x OH aq yH O l ZPH 3H PO 1 3 3 1 2 3 3 3 3 1 3 3 4 3 1 3

Mixture A is 10 ethanol by volume and mixture B is 30 ethanol by volume How many milliliters of mixture B must be added to 200 milliliters of mixture A to create a mixture that is 25 ethanol by volume 600 480 400 500 530 680

46 An alpha particle and a proton are accelerated separately by the potential difference of 2 V and ZV respectively but ratio of de Broglie wavelength of alpha particle to proton is 2 The value of Z is

respectively then x y is equal to given K HA 106 K BOH 106 a xMnO yPbO zHNO3 HMnO Pb NO3 H O then minimum integer value of z y x is A complex of platinum molecular weight 600 forms two ions in solution contains 65 Pt 23 6 CL 9 3 N and 2 H Addition of silver nitrate to

What is the concentration of the undissociated acidic in a solution of amm with a pH of 7 800 The molar concentra of dissociated acid ion is 0 02000 The of ammonia is 9 250 0 01741 0 001741 8 704 08704

18 Freundlich adsorption isotherm is represented at temperatures T T and T3 x m T Arrange the temperatures shown in the graph a T T T3 C T T3 T T2 T3 p in the increasing order as b T3 T T d T3 T T 2

What volume of 6 M HCI and 2 M HCI should be moved to get two litre of 3 M H Let the volume of 6 M HCI required to obtain 2 L of 3M HC xL Volume of 2 M HCl required 2 x L

Calculate the molar solubility of CdS in 0 10 M NH3 Enter your answer as scientific notation with the correct number of sig figs Use the e format 2 Ksp for CdS 8 0 10 27 and Kf for Cd NH3 4 1 0 107

Assertion Both rhombic and monoclinic sulphur exist as S8 but oxygen exists as 02 Reason Oxygen forms pt pt multiple bond due to small size and small bond length but pt pt bonding is not possible in sulphur A Assertion Molarity of a solution in liquid state changes with temperature R Reason The volume of a solution changes with change in temperature

A student has 470 0 mL of a 0 1246 M aqueous solution of Na CrO4 to use in an experiment She accidentally leaves the container uncovered and comes back the next week to find only solid residue The mass of the residue is 20 04 g Determine the chemical formula of this residue f the substance is a hydrate use a period instead of a dot in its formula

Estimate the pressure for hydrate formation at 55 F for the gas with following composition 92 67 methane 5 29 ethane 1 38 propane 0 182 i butane 0 478 n butane Using the Katz equilibrium Method

A wooden artifact sample gave activity 32 B particles per second while the freshly cut wood gave activity of 64 B particles per second in Geiger Muller counter Calculate the age of the wooden artifact 11 2 of C 4 5760 years a 11520 years c 2880 years b 5760 years d 1440 years

ii What happens when ZnO is heated a It turns red c It turns black iii What type of solid is silicon carbide Carborundum a Covalent b It turns blue d It turns yellow b Ionic

At 25 C vapour pressure of a volatile liquid A is 60 torr To 4 mol of A xmol of another volatile liquid B is added at 25 C The vapour pressure of the resulting solution was found to be 72 torr and mole fraction of A in the vapour phase was The value of x is 3

22 Match the Column I with Column II Column I A N 1 mol B 02 1 mol C CH4 1 mol D H O 1 mol Column II p 10 mol electrons q 8 mol protons r 6 023 1022 electrons s 10 mol protons

37 Assume 2 2 x 10 17 J of light energy is needed by the interior of human eye to see an object How many photons of yellow light with 612 nm ar needed to generate the minimum energy Use Planck s constant 6 6 x 10 34 Js an of light 3 108 m s

Derive the equation relating partial pressure of a component in a solution pa mole fraction of tha t same component in vapour phase of the mixture ya and total partial pressure pt state the law s used and how are they implemented

A flask contains hydrogen and helium gases in the ratio 1 2 at temperature 300 K The ratio of masses of helium and hydrogen molecules is 2 1 What is the ratio of average translational kinetic energies of these molecules at 500 K 1 3 5 2 5 3 3 2 1

Acidified water is electrolysed using an inert electrode The volume of gases liberated at STP is 0 168 L The quantity of charge passed through the acidified water is x C The value of is 1 F 96000 C X 10

It is found that 3 125 x 108 g atoms of Rn exist in equilibrium with 1 g of radium at 0 C and 1 atm pressure The disintegration constant of Ra is 1 48 x 10 11 s Calculate the disintegration constant of Rn

ii Calculate the amount of lime and soda required to soften 50000 L of the water sample containing Mg HCO3 2 158 mg l Ca HCO3 2 mg L MgSO4 60 mg L CaC12 25 mg L MgCl2 35 mg L NaCl 20mg L respectively answer only ii