.Which of the following statements is incorrect about electrochemical cell?
1.Salt bridge maintains the electrical neutrality of the electrolytes
2.Chemical energy is converted into electrical energy
3.Electrons are released at anode
4.Cell can work indefinitely
Posted Date:-2021-10-07 11:20:48
A compound of xenon and fluorine is found to have 53.3% Xe. What is the oxidation number of Xe in this compound? (At. mass F = 19)-
1.0
2.4
3.4
4.6
Posted Date:-2021-10-07 11:20:48
A current of 9.65 ampere is passed through the aqueous solution of NaCl using suitable electrodes for 1000 s. The amount of NaOH formed during electrolysis is
1.2.0 g
2.4.0 g
3.6.0 g
4.8.0 g
Posted Date:-2021-10-07 11:20:48
A direct current deposits 54 g of silver (At. mass = 108) during the electrolytic reaction. The same amount of electricity would deposit aluminium (At. mass = 27) from aluminium chloride solution equal to
1.4.5 g
2.5.4 g
3.54 g
4.27 g.
Posted Date:-2021-10-07 11:20:48
After two hours one sixteenth of the original quantity of a certain radioactive substances remains unchanged. The half life period of the substance is
1.30 minutes
2.40 minutes
3.25 minutes
4.45 minutes
Posted Date:-2021-10-07 11:20:48
An electrode chemical cell stops working after some time because
1.the reduction potential of one electrode becomes equal to that of the other
2.electrode potential of both the electrodes increases
3.one electrode is broken
4.None of the above
Posted Date:-2021-10-07 11:20:48
Artificial radioactivity was discovered by
1.Hahn and Strassman
2.Joliot and Irene Curie
3.Eienstein
4.Rutherford
Posted Date:-2021-10-07 11:20:48
Atom A possesses higher values of packing fraction than atom B. the relative stabilities of A and B are
1.B is more stable than A
2.+
3.A and B both are equally stable
4.Stability does not depend on packing fraction
Posted Date:-2021-10-07 11:20:48
Burning of lime to give calcium oxide is
1.oxidation process
2.redox process
3.disproportionation
4.decomposition.
Posted Date:-2021-10-07 11:20:48
Electrolytes conduct electric current:
1.by movement of electric charge through them
2.by the movement of ions
3.by the movement of molecules
4.by allowing electrons to flow through them from cathode to anode
Posted Date:-2021-10-07 11:20:48
Gamma rays are
1.Low energy waves
2.High energy protons
3.High energy electron
4.High energy electromagnetic waves
Posted Date:-2021-10-07 11:20:48
How much copper can be deposited by 2.5 Faraday of electricity?
1.2 moles
2.2.5 moles
3.1.25 moles
4.0.125 moles.
Posted Date:-2021-10-07 11:20:48
Hydrogen bomb is based on the phenomenon of
1.Nuclear explosion
2.Chemical reaction
3.Nuclear fusion
4.Nuclear fission
Posted Date:-2021-10-07 11:20:48
If half life period of radium is 1580 years its average life period will be
1.1275 years
2.2175 years
3.2275 years
4.2400 years
Posted Date:-2021-10-07 11:20:48
In order to get 9 gm of aluminium (At. mass = 27) during the electrolysis experimentHow many Faraday of electricity has to be passed?
1.3 Faraday
2.2 Faraday
3.1 Faraday
4.1.5 Faraday.
Posted Date:-2021-10-07 11:20:48
In which of the following chemical changes take place?
1.Ammeter
2.Voltameter
3.Micrometer
4.Galvanometer
Posted Date:-2021-10-07 11:20:48
In which of the following compoundvalency of carbon is 4 but its oxidation number is zero
1.methane
2.carbon dioxide
3.carbon monoxide
4.Formaldehyde.
Posted Date:-2021-10-07 11:20:48
Out of the following the one which has no charge isAlpha rays
1.Gamma rays
2.Beta rays
3.Alpha rays
4.Cathode rays
Posted Date:-2021-10-07 11:20:48
Positron emission results from the transformation of one nuclear proton into a neutron. The isotope thus produced possesses
1.intense radioactivity
2.higher nuclear charge
3.no radioactivity
4.same mass number
Posted Date:-2021-10-07 11:20:48
Radio-activity was discovered by
1.J.J. Thomson
2.Madame Curie
3.Henry Becquerel
4.Rutherford
Posted Date:-2021-10-07 11:20:48
Radium and chlorine combine to form radium chloride the compound is
1.as radioactive as the radium content
2.half as radioactive as the radium content
3.thrice as radioactive as the radium content
4.no longer radioactive
Posted Date:-2021-10-07 11:20:48
The age of most ancient geological formation is estimated byPotassium-Argon method
1.Uranium lead method
2.Radium-silicon method
3.Carbon 14 dating method
4.Potassium-Argon method
Posted Date:-2021-10-07 11:20:48
The half-life of a radioactive element is 50 days. How long will it take far its activity reduce to 1/4 of it original value?
1.100 days
2.75 days
3.50 days
4.25 days
Posted Date:-2021-10-07 11:20:48
The nucleus of radioactive element possesseslow binding energy
1.zero binding energy
2.high potential energy
3.high binding energy
4.low binding energy
Posted Date:-2021-10-07 11:20:48
The oxidation sate of phosphorus is + 3 in
1.Orthophosphoric acid
2.Phosphorus acid
3.Metaphosphoric acid
4.Pyrophosphoric acid.
Posted Date:-2021-10-07 11:20:48
The unit of radioactivity is
1.Becquerel
2.Rutherford
3.Curie
4.both Curie and Rutherford
Posted Date:-2021-10-07 11:20:48
Uranium gives stable isotope of
1.radon
2.krypton
3.polonium
4.radium
Posted Date:-2021-10-07 11:20:48
What is the fuel of atomic pile?
1.Uranium
2.Petroleum
3.Sodium
4.Thorium
Posted Date:-2021-10-07 11:20:48
When a radioactive nucleus emits an alpha particle the mass number of the atom
1.remains same and its atomic number decreases
2.decreases and its atomic number increases
3.decreases and its atomic number decreases
4.increases and its atomic number decreases
Posted Date:-2021-10-07 11:20:48
When a radioactive substance is subjected to a vacuum the rate of disintegration per second
1.increases only if the products are gaseous
2.increase considerably
3.decreases
4.is not affected
Posted Date:-2021-10-07 11:20:48
Which of the following process always involve the decrease in oxidation number?
1.Hydrolysis
2.Decomposition
3.Reduction
4.Oxidation.
Posted Date:-2021-10-07 11:20:48
Who gave the theory of radioactive disintegration?
1.Thomson and Einstein
2.Hahn and Strassmann
3.Soddy and Fajan
4.Rutherford and Soddy
Posted Date:-2021-10-07 11:20:48
Who observed that when the nucleus of uranium atom was bombarded with fast moving neutrons it becomes so very unstable that it is immediately broken into two nuclei of nearly equal mass besides other fragments?
1.Chadwick
2.Einstein
3.Rutherford
4.J.J. Thomson
Posted Date:-2021-10-07 11:20:48