Description : An organic compound (A) has a molecular weight 78 and an empirical formula CH. (A) is resistant to attack by oxidizing agents but undergoes substitution and addition reactions. X-ray analysis shows that the ... suggests that compound (A) is (a) Benzene (b) Cyclohexane (c) Toluene (d) n-Hexane
Last Answer : Benzene
Description : Assertion (A): UV radiation causes photodissociation of ozone into `O_(2)` and O, thus causing damage to the stratospheric change. Reason (R): Ozone h
Last Answer : Assertion (A): UV radiation causes photodissociation of ozone into `O_(2)` and O, thus causing damage ... true but reason is wrong D. Both are wrong
Description : Why does a H+ ion attacking a carbon-carbon double bond add to the carbon with the least number of substituents? (a) the reaction is resonance stabilized. (b) the hybrid geometry favors this ... tends to attack stable centers of negative charge. (d) a more stable carbonium ion is generated.
Last Answer : a more stable carbonium ion is generated.
Description : Which statement about the structure of benzene is not true? (a) The two Kekule structures of benzene are in equilibrium. (b) The carbon-carbon bond lengths in benzene are greater than the carbon- ... (d) The stability of benzene ring is much greater than the stability of 1,3,5- cycloheptatriene
Last Answer : The two Kekule structures of benzene are in equilibrium
Description : Electron-withdrawing groups are meta directors because : (a) the carbonium ion intermediate has a negative charge on the meta position. (b) the more stable resonance hybrid occurs with meta ... the electrophile. (d) the carbonium ion intermediate has a positive charge on the meta position
Last Answer : the more stable resonance hybrid occurs with meta attachment of the electrophile.
Description : Alkenes show geometrical isomerism due to : (a) Asymmetry (b) Rotation around a single bond (c) Resonance (d) Restricted rotation around a double bond
Last Answer : Restricted rotation around a double bond
Description : The carbon-carbon bond lengths in rank of increasing bond length is : (a) triple, double, single (b) single, double, triple (c) single, triple, double (d) triple, single, double
Last Answer : triple, double, single
Description : Assertion:Among chalcogens, catenation tendency is maximum for sulphur Reason: S-S bond is stronger than O - O single bond.
Last Answer : Assertion:Among chalcogens, catenation tendency is maximum for sulphur Reason: S-S bond is stronger ... is not correct and Statement-II is correct
Description : Explain why the water molecule has a bent shape and a bond angle less than 109.5° The electron repulsion between the two lone pairs of electrons on the oxygen of water causes the O–H bonds to squeeze close together
Last Answer : The electron repulsion between the two lone pairs of electrons on the oxygen of water causes the O–H bonds to squeeze close together
Description : Assertion :- Bond order of `O_(2)` and BN is same . Reason `O_(2) and BN` are isoelectronic
Last Answer : Assertion :- Bond order of `O_(2)` and BN is same . Reason `O_(2) and BN` are isoelectronic ... is False. D. If both Assertion & Reason are false
Description : Assertion (A) Both rhombic and monoclinic sulphur exist as `S_(8)` but oxygen exists as `O_(2)`. Reason (R ) Oxygen forms `ppi-ppi` multiple bond due
Last Answer : Assertion (A) Both rhombic and monoclinic sulphur exist as `S_(8)` but oxygen exists as `O_ ... Statement-I is not correct and Statement-II is correct
Description : Which of the following statements are correct concerning benzene? (a) Benzene is a planar molecule. (b) The six carbon-carbon bonds have the same length. (c) Benzene has alternating single and double bonds. (d) (a) and (b)
Last Answer : (a) and (b)
Description : Assertion : In aDNA molecule, A-T rich parts melt before G-C rich parts. Reason : In between A and T there are three H-bond, whereas in between G and
Last Answer : Assertion : In aDNA molecule, A-T rich parts melt before G-C rich parts. Reason : In between A ... false. D. If both assertion and reason are false.
Description : What are alkenes having two double bonds separated by one single bond known as?
Last Answer : ANSWER: CONJUGATED DIENES
Description : Which of the following is not characteristic of a p bond? (a) A p bond results from lateral overlap of atomic orbitals (b) A p bond may be formed by the overlap of p - or d - orbitals (c) p bonds are obtained from hybrid orbitals (d) p bonds is formed when a bond already exists
Last Answer : Ans:(c)
Description : Assertion : Phenols are more acidic than aliphatic alcohols. Reason : Phenoxides are stabilized by resonance.
Last Answer : Assertion : Phenols are more acidic than aliphatic alcohols. Reason : Phenoxides are stabilized by resonance. ... D. A is incorrect but R is correct
Description : What happens when a chemical bond is formed? (1) energy is always absorbed (2) energy in always released (3) more energy is released than is absorbed (4) energy is neither released nor ... as potential energy. Upon the breaking of these bonds the energy is released thereby creating usable energy.
Last Answer : Silver nitrate solution is kept in brown bottles in laboratory because - (1) it reacts with ordinary white bottles (2) brown bottles stops the passage of light through it (3) brown bottles do not react with it (4) brown bottles react with it
Description : In an oxygen molecule, two atoms are united by - (1) one bond (2) two bonds (3) three bonds (4) four bonds
Last Answer : (2) two bonds Explanation: Two oxygen atoms can both achieve stable structures by sharing two pairs of electrons as in the diagram. Two electrons of each of the atom in the oxygen molecule ... is shown conventionally by two lines joining the atoms. Each line represents one pair of shared electrons.
Description : Is the bond energy of all the four C-H bonds in CH4 molecule equal? If not then why ? How is C-H bond energy then reported?
Last Answer : Ans. No because after breaking of C-H bonds one by one, the electronic environments change. The reported value is the average of of the bond dissociation energies of the four C-H bonds.
Description : In an oxygen molecule, two atoms are united by (1) one bond (2) two bonds (3) three bonds (4) four bonds
Last Answer : two bonds
Description : Assertion:- All the organelles of eukaryotic cells are surrounded by either single or double membrane. Reason:- In eukaryotic cell none of cell organe
Last Answer : Assertion:- All the organelles of eukaryotic cells are surrounded by either single or double membrane. ... D. If both Assertion & Reason are false.
Description : How do double bonds in the rubber molecule influence their structure and reactivity ?
Last Answer : Due to presence of double bond the rubber molecule show cis-configuration because which the polymer chains can not come close to each other and get boiled but as they have their ... Waals intraction between the molecules consequently they get elastic property, solubility in organic solvents etc.
Description : In double bond, how many sigma and Pi bonds are present in it ?
Last Answer : Double bond = 1 Sigma bond and one Pi bond Among sigma and Pi bonds which is the stronger one Sigma bond is Stronger than pi bond
Description : Which brief statement most accurately describes why alkenes react the way they do? (a) C=C double bonds are weak. (b) A π bond is lost but a stronger σ bond is gained. (c) C=C double bonds are unstable. (d) C=C π bonds are attacked by nucleophiles.
Last Answer : A π bond is lost but a stronger σ bond is gained.
Description : Carbon-carbon double bonds consist of : (a) one σ bond, one π bond (b) two σ bonds, one π bond (c) one σ bond, two π bonds (d) two σ bonds, two π bonds
Last Answer : one σ bond, one π bond
Description : Catenation is a property of the carbon atom which describes its ability to (a) bond with other carbon atoms (b) form double and triple bonds (c) exist in plant and animal form (d) form bonds in its ground state
Last Answer : bond with other carbon atoms
Description : In 2-butene, which of the following bonds prevents the atoms at each end of the bond from rotating with respect to each other. Is it an: w) ionic bond x) sigma bond y) strong bond z) double bond
Last Answer : ANSWER: Z -- DOUBLE BOND
Description : Asseration: Number of `S-S` bonds in `H_(2)S_(n)O_(6)` is (n-1). Reason: `H_(2)S_(n)O_(6)` shows `HO_(3)S-underset((n-2))(S)-SO_(3)H`
Last Answer : Asseration: Number of `S-S` bonds in `H_(2)S_(n)O_(6)` is (n-1). Reason: `H_(2)S_(n)O_(6)` shows `HO_(3)S-underset((n-2))(S)-SO_(3)H`
Description : Phenol is more reactive than benzene towards electrophilic substitution reaction. In case of Phenol, the intermediate carbocation is more resonance st
Last Answer : Phenol is more reactive than benzene towards electrophilic substitution reaction. In case of Phenol, the ... D. A is incorrect but R is correct
Description : The number of O atoms having `sp^(2)` hybridisation in `P_(4)O_(10)` molecule is:
Last Answer : The number of O atoms having `sp^(2)` hybridisation in `P_(4)O_(10)` molecule is:
Description : Assertion `:-` In the tissue high `P_(O_(2))`, low `P_(CO_(2))`, higher `H^(o+)` concentration conditions are favourable for dissociation of oxygen fr
Last Answer : Assertion `:-` In the tissue high `P_(O_(2))`, low `P_(CO_(2))`, higher `H^(o+)` ... Reason is False. D. If both Assertion & Reason are false.
Description : The correct order of O - O bond length in `O_(2)H_(2)O_(2)` and `O_(3)` is
Last Answer : The correct order of O - O bond length in `O_(2)H_(2)O_(2)` and `O_(3)` is A. `O_(2)gtO_(3)gtH_(2)O_( ... )O_(2)gtO_(2)` D. `H_(2)O_(2)gtO_(3)gtO_(2)`
Description : 1. Who is the executive head of a Municipal Corporation? 2. What is the maximum number of hydrogen bonds in a H2 O molecule? 3. How is the contribution of agriculture to India's ... largest number of sugar mills? 20. Among which class did Indian National Congress find wide acceptance initially?
Last Answer : Answer : 1. Commissioner 2. 4 3. Decreasing 4. Sone 5. Aurangzeb 6. Arjun Singh 7. B. H. C. 8. By consensus 9. Narmada 10. Mir Jafar 11. 30 - 300 MHz 12. Satellite launching 13. National ... 15. Agra 16. Ecology 17. Government of India Act, 1935 18. Urea 19. Uttar Pradesh 20. Educated middle class
Description : Assertion `:-` Haemoglobin can not get saturated with oxygen more than `97%`. Reason `:-` With a rise in `PO_(2)`, the affinity between `O_(2)` & haem
Last Answer : Assertion `:-` Haemoglobin can not get saturated with oxygen more than `97%`. Reason `:-` With a ... False. D. If both Assertion & Reason are false.
Description : Assertion :- In acidic medium, equivalent weight of `K_(2)Cr_(2)O_(7)` is equal to `294//6`. Reason :- In acidic medium, `Cr_(2)O_(7)^(-2)` is reduced
Last Answer : Assertion :- In acidic medium, equivalent weight of `K_(2)Cr_(2)O_(7)` is equal to `294//6`. ... is False. D. If both Assertion & Reason are False.
Description : Assertion : In the reaction, `(1)/(2)O_(2)+F_(2)rarrOF_(2)` Fluorine is oxidant. Reason :- Fluorine cannot show positive oxidation state.
Last Answer : Assertion : In the reaction, `(1)/(2)O_(2)+F_(2)rarrOF_(2)` Fluorine is oxidant. Reason :- ... is False. D. If both Assertion & Reason are False.
Description : Assertion: Reaction of `SO_(2)` and `H_(2)S` in the presence of `Fe_(2)O_(3)` catalyst gives elemental sulphur. Reason: `SO_(2)` is a reducing agent.
Last Answer : Assertion: Reaction of `SO_(2)` and `H_(2)S` in the presence of `Fe_(2)O_(3)` catalyst gives ... is False. D. If both Assertion & Reason are False.
Description : Assertion :- A sol of `As_(2)S_(3)` prepared by the action of `H_(2)S` on `As_(2)O_(3)` is negatively charge. Reason :- Due to adsorption of `S^(-2)`
Last Answer : Assertion :- A sol of `As_(2)S_(3)` prepared by the action of `H_(2)S` on `As_(2)O_(3) ... Reason is False. D. If both Assertion & Reason are False.
Description : Which of the bonds in Ethyl alcohol (CH3CH2OH) will undergo heterolytic bond fission most readily? (a) O–H (b) C–H (c) C–O (d) C–C
Last Answer : O–H
Description : Assertion : The primitive atmosphere was reducing one i.e., without oxygen. Reason : In the atmosphere, oxygen was involved in forming ozone.
Last Answer : Assertion : The primitive atmosphere was reducing one i.e., without oxygen. Reason : In the ... . If both the assertion and reason are false.
Description : Assertion (A) : Presently, the global atmosphere is warming up. Reason (R): The depletion of stratospheric ozone layer has resulted in increase in ult
Last Answer : Assertion (A) : Presently, the global atmosphere is warming up. Reason (R): The depletion of ... true but reason is wrong D. Both are wrong
Description : Assertion : In presence of ozone, mercury loses its meniscus and sticks to glasses. This is called tailing of mercury Reason: Tailing of mercury is du
Last Answer : Assertion : In presence of ozone, mercury loses its meniscus and sticks to glasses. This is called ... -I is not correct and Statement-II is correct
Description : Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): Because the bonds of adsorbed molecules are broke
Last Answer : Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): ... D. If both Assertion & Reason are False.
Description : Assertion : Phenol has lower boiling point then water Reason : Water forms more number of hydrogen bonds
Last Answer : Assertion : Phenol has lower boiling point then water Reason : Water forms more number of hydrogen ... false D. Assertion is false, Reason is true
Description : Assertion : A major advantage of tissue culture is protoplast fusion. Reason : A hybrid is formed by the fusion of naked protoplasts of two plant.
Last Answer : Assertion : A major advantage of tissue culture is protoplast fusion. Reason : A hybrid is formed ... false D. If both assertion and reason are false
Description : Assertion : In case of vegetatively propagated crops, pure line selection is not requried. Reason : Hybrid vigour is mostly used in vegetatively propa
Last Answer : Assertion : In case of vegetatively propagated crops, pure line selection is not requried. Reason : ... D. If both assertion and reason are false
Description : Assertion: The study of biomolecules is called Molecular biology. Reason: Cell is a type of molecule.
Last Answer : Assertion: The study of biomolecules is called Molecular biology. Reason: Cell is a type of molecule. A. If ... wrong D. If both As and R are wrong.
Description : What are molecules that have alternating single and double bonds are called?
Last Answer : These are molecules in a conjugated system.