Nuclear chemistry Questions and Answers

is m charge is and it is accelerated from rest through a potential difference of V volt The velocity acquired by electron will be Question Type Single Correct Type 1 2 C V eV m 7orn

A near UV photon of 300nm is absorbed by a gas and then re emitted as two photons One photon is red with wavelength 760nm Hence wavelength of the second photon is A B kipped C D 1060 nm 496 nm 300 nm 215 nm G

Consider the following nuclear reactions involving X Y X Y He Y 0 8 H If both neutrons as well as protons in both the sides are conserved in uclear reaction then moles of neutron 4 6 gm of X A 2 4 NA C 4 6 B 2 4 D 0 2 NA

2 5 When 0 1 mol MnO4 is oxidised the quantity of electricity required to completely oxidise MnO to MnO4 is a 96500 C c 9650 C AIPMT 2014 b 2x96500 C d 96 50 C for fat wt 108 displaced b 1

With the help of following reactions arrange metals A B D and E in decreasing order of their reactivity a B ANO3 BNO3 A b A HCI ACI c D ECI DCI E d D HNO3 No reaction Question Type Single Correct Type 1 B D E A H 2 2 B A D E 3 E D B A

44 Which one of the following combinations will give the highest stability to a nucleus 15 atomic number Z and mass number N Kerala PMT 200 a Even Z and odd N c Even Z and even N e Same value of Z and N nsp b Odd Z and even N d Odd Z and odd N TAIMS 200

a ithe he uncertainty principle is AE x At 2 t h 4 x 3 P subset NEET 2017 C b Half filled and fully filled orbitals have greater stability due to greater exchange energy greater symmetry and more balanced arrangement c The energy of 2s orbital is less than the energy of 2p orbital in case of hydrogen lik atoms h d de Broglie s wavelength is given by velocity of the particle mv where m mass of the particle v group

Ch31 P34 A rare decay mode has been observed in which 222 Ra emits a 14C nucleus The decay equation is 222 Ra AX 14C and you have identified unknown nuclide AX in the problem of Section 31 4 You ll need to use that answer in this problem a Find the mass change from the parent nuclide to the daughter nuclides Enter your answer to 7 SigFigs The mass change answers in nuclear decays must be correct to 6 places pas the decimal point Units are not required for this problem U b Find the energy emitted in the decay in units of MeV The mass of 222 Ra is 222 015353 u Enter your answer to 3sigFigs in MeV Units are not required in this answer

The analysis of a rock shows that the relative number of Pb206 and U238 atoms is Pb U 0 25 If t1 2 of U238 is 4 5 x 10 years then the age of the rocks will be A B C D 2 303 0 693 2 303 0 693 2 303 0 693 2 303 0 693 5 4 5 10 log 2 4 5 10 log 1 4 5 10 log 4 4 5 10 log 4 5

338 U is the element of III d B group It undergoes decay as follows 238 U 92 A A will be of III B group B A will be of IB group C B will be of II A alkaline earth metal group BBC which of the following statements is are correct D C is the isotope of 338 U 92

for f 18 The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is a is Bohr 2h Given as then x 2 2 x maz

66 If 10 g of H2 reacts with 42 g of N2 then identify the correct statement 1 1 mol of H is left in excess 2 N is the limiting reagent 3 2 5 mol of NH3 is formed 4 0 5 mol of N is left in excess 67 Which of the following pairs of species are isodiapheres 1 H and D 3 30 Si 4 and 1P15 2 15N and 708 4 40 A18 and 40K19

A radioactive material has mean lives of 1620 years and 660 years for a and emissions respectively The material decays by simultaneous a and emission The time in which of the 4 material remains intact is 1 4675 years 2 720 years 3 650 years 4 324 years

What particle is needed to complete the following equation 56 Mn 25 O O O 56 27 Co 56 Fe 26 27 25 Mn 58 20 Cr D

If dipole moment of AB molecule is 1 6 10 2 Cm and distance of A B bond is 1 6 then percentage ionic character of the compound will be 62 5 75 1 70 5

cop In photoelectric effect if a weak intensity radiation instead of strong intensity of suitable frequency is used then 1 Photoelectric effect will get delayed 2 Photoelectric effect will not take place 3 Maximum kinetic energy will decrease 4 Saturation current will decrease

JLLUSTRATION 4 If the atomic masses of lithium helium and proton are 7 01823 amu 4 00387 amu and 1 00815 amu respectively calculate the energy that will be evolved in the reaction Li7 H1 2He4 energy Given that 1 amu 931 MeV

ILLUSTRATION 9 Find out the total number of a and 90 B particles emitted in the disintegration of Th232 to 82Pb 208

ILLUSTRATION 5 Calulate the mass defect and binding energy per nucleon for 27C059 The mass of Co59 58 95 amu mass of hydrogen atom 1 008142 amu and mass of neutron 1 008982 amu

53 When a electron in H atom jumps from n 4 to n 1 ultra violet light is emitted if the transition corresponds to n 4 to n 2 which of the following light will be emitted a ultraviolet c infrared b visible d None of these

238 A closed vessel with rigid walls contains 1 mol of 22U and 1 mol of air at 298 K Considering 92 92 82 complete decay of 232 Uto 20 Pb the ratio of the final pressure to the initial pressure of the system at 298 K is 2015

Match the List I Phenomenon associated with electromagnetic radiation with List II Part of electromagnetic spectrum and select the correct code from the choices given below the lists List Il Visible radiation Microwave 1 II III IV List I Doublet of sodium A Wavelength corresponding to temperature associated with B the isotropic radiation filling all space Wavelength emitted by atomic hydrogen in interstellar C space Wavelength of radiation arising from two close energy D levels in hydrogen 1 1 A II B III C IV C 2 1 A II B III B IV C 3 1 B II A III D IV A 4 1 D 11 C III A IV B Short radiowave X rays 2014

The half life period of a first order reaction is 10 minutes The time required for the concentration of the reactant to change from 0 08 M to 0 02 M is B 20 min D 40 min A 10 min C 30 min

A nuclear explosion has taken place leading to increase in concentration of C14 in nearby areas C14 concentration is C in nearby areas and C in areas far away If the age of the fossil is determined to be T and T at the places respectively then A The age of the fossil will increase at the place where explosion has taken place and T T 1 C In 2 C B The age of the fossil will decrease at the place where explosion has taken place and T T In C 2 C C The age of fossil will be determined to be same T C T C D

Negative Marks 2 in all other cases When photons of energy 4 25 eV strike the surface of a metal A the ejected photoelectrons have maximum kinetic energy T expressed in eV and de Broglie wavelength The maximum kinetic energy of photoelectrons liberated from another metal B by photons of T energy 4 2 eV is T T 1 50 eV If the de Broglie wavelength of these photoelectrons is 22 then which is correct B A A B C D The work function of A is 2 25 eV The work function of B is 3 70 eV TA 2 00eV TB 2 75eV Correct Options A B C D Your Answers AC

Select the correct option s 8 A Specific activity of U235 is greater than specific activity of U O All U is U235 B Activity of 1 mol U235 is greater than activity of 1 mol U O All U is U235 C Decay constant of U235 is same whether it is pure U235 or U O All U is U235 D Rate of radioactive disintegration increases with increase in temperature 3 8

6 The minimum energy required for the emission of photoelectron from the surface of a metal is 4 95 10 9 J Calculate the critical frequency and the corresponding wavelength of the photon required to eject the electron h 6 6x 10 34 J sec

The enthalpies of neutralization of a weak base AOH and a strong base BOH by HCl are 12250 cal mol and 13000 cal mol respectively When one mole of HCl is added to a mixture containing 1 mole of AOH and 1 mole of BOH the enthalpy change was 12500 cal mol In what ratio is the acid distribution between AOH and BOH g 2 1 3 1 2 2 2 3 4 None of these

256 For a crystal the angle of diffraction 20 is 90 and the second order line has a d value of 2 28A The wave length in A of X rays used for Bragg s diffraction is 2 2 0 4 4 00 3 2 28 Eamcet 2008 E 1 1 61

2 9 10 yr 19K 40 A 10 yr 20 40 18 Ar40 Ratio of atoms of Ar to K in a rock sample is 3 10 Calculate age of rock sample assu that source of Ar is radioactive decay of K40 only and no Ar was present at the ti formation of rock

The volume of the blood in a patient is estimated by recording the activity of Na 4 administered into the patient s blood Find the volume in of the blood if the activity after 25 hrs is 8 dpm me Given the initial activity of Na24 sample is 2 10 Bq when administered the t for Na 4 15 hrs use 32 3 3 1 2

3 Calculate the binding energy per nucleon of Li isotope which has the isotopic mass of 7 016 amu The individual masses of neutron and proton are 1 008665 amu and 1 007277 amu respectively and the mass of electron 0 000548 amu

A pure radio chemical preparation was observed to disintegrate at the rate of 2140 counts minutes at 12 35 P M At 3 55 P M of the same day the disintegration rate of the sample was only 535 count minutes What is the half life of the material

Ac227 has a half life of 22 year w r t radioactive decay The decay follows two parallel paths one leading the Th 27 and the other leading to Fr223 the percentage yields of these two daughters nucleides are 2 and 98 respectively What is the rate constant in yr for each of the separate paths

In disintegration reaction represented below B C 2 2 A t 2 1 t 2 2 It is found that the radioactive element B is in equilibrium with A If N and N are the number c radioactive elements A and B respectively then N where and 2 are average life of A and B respectively N N N A B C N N T T2 2 2 2 1 2 2 t 2 1 where 2 2 and transient equilibrium is achieved t 2 1 N 2 in the value of n D

12 3 Bi2 t 130 sec decays T1207 81 by 83 83 a emission In an experiment starting with 5 moles of Bi211 how much pressure would be developed in a 350 L closed vessel at 25 C after 760 sec Antilog 1 759 57 41 1 0 68 atm 2 0 22 atm 3 0 34 atm 4 0 54 atm to

A 100 Fl 50 153 151 Mass amu to determine the atomic mass of europium The peak representing Eu 151 has an exact mass of 150 91986 amu and percent intensity is assumed be to exactly 91 610 the peak representing Eu 153 has an exact mass of 152 92138 amu and percent inten 100 00 Express your answer to two decimal places with the appropriate units View Available Hint s 11 Intensity

e Hall coefficient of a semiconductor is 3 22 X 10 power 4 m3 C Its resistivity is 9 X 10 power 3 mm The mobility of charge carriers will be OPTIONS 0 0035 X 10 power 2 m2 Vs 035 X 10 power 2 m2 Vs 0 35 x 10 power 2 m2 Vs

Let s say you re a diver and want to use an oxygen tank to breath under water At 250 ft the P 02 8 38 atm and the P 02 in the tank is 0 21 atm the same as it is in the air we breath at 1 atm normally What is the mole of oxygen in the tank Start by writing the equation that you ll use to solve the problem 1 2 4 6 8 9 2 5

Two isotopes X and Y of atomic mass 10 and 20 respectively are mixed in equal amo mass After 30 days their mass ratio if found to be 4 1 If isotope X has half life of 10 day is the half life of Y in days

The uranium currently present on Earth consists of two isotopes 238U at 99 28 and 235U at 0 72 The half lives are 4 51x109 and 7x108 years respectively Calculate the time that has elapsed since the relative abundance in nature of each isotope was 50 Relative abundances are given in atomic percentage

Phosphorus 32 is a commonly used radioactive nuclide in biochemical research particularly in studies of nucleic acids The half life of phosphorus 32 is 14 3 days What mass of phosphorus 32 is left from an original sample of 175 mg of Na332PO4 after 30 5 days Assume that the atomic mass of 32P is 32 0

4 How much energy must be supplied to break a single sodium 23 nucleus into separated protons and neutrons if the nucleus has a mass of 22 983733 amu How much energy is required in BTU mole of this nucleus 15

Determine the half life of the substance that decays from A to A in time t A51 A 19 t 20 hours The half life of the substance that decays from 51 to 19 in 20 hours is hours Do not round until the final answer Then round to one decimal place as needed

Mass defect in the nuclear reactions may be expressed in terms of the atomic masses of the parent and daughter nuclides in place of their nuclear masses 10 The mass defect of nuclear reaction Be 0 B 0 e is 5 A Am At mass of Be 0 At mass of B 0 10 10 of B 0 mass of one electron B Am At mass of Be 0 At mass C Am At mass of Be 0 At mass of B 0 mass of one electron 10 10 m At mass of Belo At mass of B 0 mass of two electrons 10 10 RA0064

What is Radioactivity Why does it occur

3 He and Ar 4 O and N HT023 216 For an adiabatic expansion of a perfect gas th value of AP P is equal to 1 T AV V 3 y AV V 2 AV V 4 AV V HT0235

system en the 30 210 The temperature of 5 moles of a gas which was held at constant volume was changed from 100 C to 120 C The change in internal energy was found to be 80 joules The total heat capacity of the gas at constant volume will be equal to 1 8 J K 2 0 8 J K 3 4 0 J K 4 0 4 J K ion 2017 210 T0227 ne is W T then heat HT0232

204 When a system changes from one to another state the value of work done 1 Depends on the force acting on the system 2 Depends on the nature of material present in a system 3 Does not depend on the path 4 Depends on the path HT0225

60 The pressure exerted by a gas in P If the mass of molecules becomes half and their velocities become double then pressure will become 2 Po 3 2P 12 2 P 1 4 4P 16