Description : Pyrrole is less basic than pyridine because the lone-pair of electrons on Natom in pyrrole (a) is part of the delocalized π molecular orbital. (b) is not part of the delocalized π molecular orbital. (c) resides in sp2 hybrid orbital (d) resides in sp hybrid orbital
Last Answer : is part of the delocalized π molecular orbital.
Description : Pyridine is less basic than trimethylamine because the lone-pair of electrons on N-atom in pyridine resides in (a) sp2 hybrid orbital (b) sp hybrid orbital (c) sp3 hybrid orbital (d) p-orbital
Last Answer : sp2 hybrid orbita
Description : The delocalized π system in benzene is formed by a cyclic overlap of 6 orbitals. (a) s (b) p (c) sp (d) sp2
Last Answer : p
Description : Which of the following statements about benzene is correct? (a) All of the carbon atoms are sp3 hybridized. (b) It has no delocalized electrons. (c) The carbon-carbon bond length is longer than that of ethane. (d) It is a planar molecule.
Last Answer : It is a planar molecule.
Description : Which of the following statements are correct concerning delocalized electrons? (a) Electrons do not belong to a single atom. (b) Electrons are not confined to a bond between two atoms (c) Electrons are shared by three or more atoms. (d) (a), (b) and (c)
Last Answer : (d) (a), (b) and (c)
Description : Which of the following is incorrect? (a) Resonance stabilization is the extra stability a compound gains from having delocalized electrons. (b) Delocalized electrons destabilize a compound. (c) The greater ... stable resonance contributors, the greater is the resonance stabilization. (d) (a) and (c)
Last Answer : Delocalized electrons destabilize a compound
Description : What are free electrons or delocalized electrons?
Last Answer : Valence electrons
Description : Molecular oxygen is said to be paramagnetic. This indicates that molecular oxygen: w) is a gas at room temperature x) forms molecules containing two oxygen atoms y) has an approximate molecular weight of 32 z) has unpaired electrons
Last Answer : ANSWER: Z -- HAS UNPAIRED ELECTRONS
Description : Ethyl alcohol containing 9.5% methyl alcohol and 0.5 % pyridine is called
Last Answer : Ethyl alcohol containing 9.5% methyl alcohol and 0.5 % pyridine is called A. Spirit B. Denaturated spirit C. Rectified spirit D. Absolute alcohol
Description : What purpose does FeCl3 serve in the electrophilic aromatic substitution reaction between chlorine and benzene? (a) It serves as a radical initiator to produce the chlorine radical needed to propagate the ... by reacting with the Cl2 and thereby activates it toward attack by benzene's π electrons.
Last Answer : It serves as a Lewis acid catalyst by reacting with the Cl2 and thereby activates it toward attack by benzene’s π electrons.
Description : Aromatic molecules contain __________ π electrons. (a) no (b) 4n + 2 (with n being an integer) (c) 4n + 2 (with n being 0.5) (d) 4n (with n an integer)
Last Answer : 4n + 2 (with n being an integer)
Description : What is a molecular orbital ?
Last Answer : : The overlap of two orbitals creates a field with a normal density of electron clouds in the middle of the nucleus of the two atoms , called the molecular orbital. In this case the net gravitational force of both atoms is highest.
Description : Distinguish between atomic orbital and molecular orbital.
Last Answer : Ans An atomic orbital is monocentric while a molecular orbital is polycentric.
Description : Distinguish between bonding molecular orbital and anti-bonding molecular orbital.
Last Answer : Ans.(i)The bonding molecular orbital has lower energy and hence greater stability than the corresponding antibonding molecular orbital. (ii) Just as the electron probability distribution around a ... formed by the subtraction of wave function of atomic orbital is called antibonding molecular orbital
Description : Give salient features of Molecular orbital theory
Last Answer : Ans (i) The electrons in a molecule are present in the various molecular orbitals as the electrons of atoms are present in the various atomic orbitals. (ii) The atomic orbitals of comparable ... in accordance with the aufbau principle obeying the Pauli's exclusion principle and the Hund's rule.
Description : Two electrons in an orbital are differentiated by which of the following? (1) Magnetic quantum number (2) Spin quantum number (3) Principal quantum number (4) Azimuthal quantum number
Last Answer : (2) Spin quantum number Explanation: Spin quantum number is the is the fourth quantum number that differentiates two electrons in the same orbital. The Pauli exclusion principle states that "no two ... atom. Each electron must have a different spin or occupy a different shell from any other.
Description : Electrons in the highest energy level of an atom are called _______. (1) valence protons (2) orbital protons (3) valence electrons (4) orbital electrons
Last Answer : (3) valence electrons Explanation: The outermost orbital shell of an atom is called its valence shell, and the electrons in the valence shell are valence electrons.
Description : The lone-pair electrons of the methyl anion occupy a __________ orbital. (a) s (b) sp (c) sp2 (d) sp3
Last Answer : sp3
Description : The orbital angular momemtum quantum number indicates which one of the following? w) the average distance of the electrons from the nucleus x) the direction of spin of the electron y) the shape of the orbital z) the position about the three axes in space of the orbital
Last Answer : ANSWER: Y -- THE SHAPE OF THE ORBITAL
Description : What is the maximum number of electrons that can occupy an s atomic orbital?
Last Answer : ANSWER: 2
Description : Which of the following is a necessary characteristic for electrons that share an s orbital? w) coplanar spins x) parallel spins y) opposite spins z) none of these
Last Answer : ANSWER: Y -- OPPOSITE SPINS
Description : What is the maximum number of electrons that can occupy an s orbital?
Last Answer : ANSWER: TWO
Description : How many electrons can occupy an s orbital? w) one x) two y) three z) four
Last Answer : ANSWER: X -- TWO
Description : Two electrons in an orbital are differentiated by which of the following ? (1) Magnetic quantum number (2) Spin quantum number (3) Principal quantum number (4) Azimuthal quantum number
Last Answer : Spin quantum number
Description : When there are two electrons in the same orbital, they have: (1) same spin (2) opposite spin (3) same or opposite spin (4) no spin
Last Answer : opposite spin
Description : The maximum number of electrons in p-orbital with n = 6, m = 0 is
Last Answer : The maximum number of electrons in p-orbital with n = 6, m = 0 is A. 2 B. 6 C. 10 D. 14
Description : A solution containing 30 g of non-volatile solute exactly in 90 g of water has a vapour pressure of 2.8 kPa at 298 K. Further 18 g of water is added to this solution. The new vapour pressure ... K. Calculate (i) the molecular mass of solute and (ii) vapour pressure of water at 298 K -Chemistry
Last Answer : For a very dilute solution ∴ Molecular mass, MB = 34 g/mol.
Description : Which of the following statement is not correct from the point of view of molecular orbital ?
Last Answer : Which of the following statement is not correct from the point of view of molecular orbital ? A. `Be_(2)` ... is `pi_(2px)=pi_(2py) lt sigma_(2pz)`
Description : What Molecular orbital interactions are not possible because the atomic orbitals have overlapping electron densities.?
Last Answer : Need answer
Description : The area of the circle that can be inscribed in a square of side 6 cm is (a) 36 π cm 2 (b) 18 π cm 2 (c) 12 π cm 2 (d) 9 π cm 2
Last Answer : (d) 9 π cm 2
Description : What is the maximum number of electrons that can be accommodated in an orbital?
Last Answer : Answer: 2.
Description : Assertion:- `N_(2)^(+)` is more stable than `N_(2)^(-)` Reason:- `N_(2)^(+)` has less electrons in antibonding orbital .
Last Answer : Assertion:- `N_(2)^(+)` is more stable than `N_(2)^(-)` Reason:- `N_(2)^(+)` has ... the Reason is False. D. If both Assertion & Reason are false
Description : How many totals electrons can the d orbital hold?
Last Answer : 10
Description : How many electrons are in the N1 orbital?
Description : A substance emits energy which is detected as a line emission in the visible region using a spectroscope. The origin of this energy is (a) Vibrational energy of the molecules (b) Rotational energy of the molecules (c) Energy of orbital electrons (d) Energy of protons in the nucleus.
Last Answer : Ans:(c)
Last Answer : (2) Spin quantum number Explanation: Spin quantum number is the fourth quantum number that differentiates two electrons in the same orbital.
Description : Which one of the following statements is WRONG? (A) A singlet or triplet state may result when one of the electrons from the HOMO is excited to higher energy levels (B) In an ... the electron from the singlet excited state returns to ground state, the molecule always shows fluorescence phenomenon
Last Answer : (C) Triplet excited state is more stable than the singlet excited state
Description : How can you identify a delocalized and pi system is present?
Description : How many p orbitals result when delocalized and pi orbitals form?
Description : If the number of carbon atom in a π-system is 5 the secular determinant will be of the order A) 5 x 5 B) 6 x 6 C) 5 x 6 D) 4 x 4
Last Answer : A) 5 x 5
Description : Which of the following reagents will react with furan to form 2-furansulfonic acid? (a) SO3 in pyridine at 100°C (b) Dilute H2SO4 at 200°C (c) SO2 at 100°C (d) Dilute H2SO4 at 100°C
Last Answer : SO3 in pyridine at 100°C
Description : Furan reacts with ammonia in the presence of alumina at 400°C to give (a) Pyridine (b) Furfural (c) Pyrrole (d) Furoic acid
Last Answer : Pyrrole
Description : Pyridine undergoes nuclophilic substitution with NaNH2 at 100°C to form (a) 2-Aminopyridine (b) 3-Aminopyridine (c) 4-Aminopyridine (d) None of these
Last Answer : 2-Aminopyridine
Description : Pyridine reacts with a mixture of KNO3 and H2SO4 at 300°C to give (a) 1-Nitropyridine (b) 2-Nitropyridine (c) 3-Nitropyridine (d) 4-Nitropyridine
Last Answer : 3-Nitropyridine
Description : Pyridine undergoes electrophilic substitution with fuming H2SO4 at 350°C to give (a) 2-Pyridinesulfonic acid (b) 4-Pyridinesulfonic acid (c) 3-Pyridinesulfonic acid (d) None of these
Last Answer : 3-Pyridinesulfonic acid
Description : Pyridine reacts with HCl to form (a) Pyridinium chloride (b) 2-Chloropyridine (c) 3-Chloropyridine (d) All of these
Last Answer : Pyridinium chloride
Description : The ‘N’ atom in pyridine is (a) sp3 hybridized (b) sp2 hybridized (c) sp hybridized (d) cannot be predicted
Last Answer : sp2 hybridized
Description : Which of the following heterocyclic compounds is not aromatic? (a) Pyridine (b) Pyrrole (c) Furan (d) Piperidine
Last Answer : Piperidine
Description : A compound gives a positive Tollens' test but negative Ninhydrin test. It is (a) a protein (b) an amino acid (c) a monosaccharide (d) pyridine
Last Answer : a monosaccharide