Description : Which statement about the carbonyl group of ketones and aldehydes is true? I. It can attract nucleophiles. II. It can attract electrophiles. III. It tends to undergo addition reactions. IV. It tends to undergo substitution reactions. (a) I and III (b) II and IV (c) I, II, and III (d) I, III, and IV
Last Answer : I, II, and III
Description : A family of organic compounds whose molecules will add water under an acid catalysis and change into alcohols are the: w) alkenes x) alkanes y) aromatic hydrocarbons z) cycloalkanes
Last Answer : ANSWER: W -- ALKENES
Description : What are characteristic of aromatic hydrocarbons?
Last Answer : Principal characteristics of aromatic hydrocarbons are:- the contain benzenic rings- frequently they have an agreeable odor- they burn with soot; this is a disadvantage- the ratio carbon/hydrogen is great
Description : What property of low-molecular weight aldehydes and ketones accounts for the magnitude of their boiling points? (a) The ability to form strong H-bonds between their molecules. (b) The ability of ... other polar molecules. (d) The ability of the carbonyl group to attract electrophiles and form bonds.
Last Answer : The ability of the polar carbonyl group to attract other polar molecules.
Description : Homolytic fission of covalent bond between carbon atoms will produce : (a) Two carbonium ions (b) Two molecules (c) Free radicals (d) Carbonium ion and carbanion
Last Answer : Free radicals
Description : Wax used for making candle is chemically a mixture of – (1) aliphatic hydrocarbons (2) aromatic hydrocarbons (3) cyclic hydrocarbons (4) aliphatic and aromatic hydrocarbons
Last Answer : (1) aliphatic hydrocarbons Explanation: An aliphatic compound is a hydrocarbon compound containing carbon and hydrogen joined together in straight chains, branched trains or non-aromatic rings ... naturally occurring. Waxes are organic compounds that characteristically consist of long alkyl chains.
Description : Aromatic hydrocarbons are also called : (a) Arenes (b) Huckel's compounds (c) Trienes (d) Alkoxy compounds
Last Answer : Arenes
Description : Which of the following methods can be used to increase the octane rating of gasoline? (a) Adding branched-chain alkanes (b) Adding tetraethyllead (c) Adding aromatic hydrocarbons (d) All of these
Last Answer : All of these
Description : How many isomeric aromatic hydrocarbons are possible for C8H10? (a) 3 (b) 4 (c) 5 (d) 6
Last Answer : 4
Description : Wax used for making candle is chemically a mixture of (1) aliphatic hydrocarbons (2) aromatic hydrocarbons (3) cyclic hydrocarbons (4) aliphatic and aromatic hydrocarbons
Last Answer : aliphatic hydrocarbons
Description : Answer: a, b, c, d Free oxygen radicals are chemical species that are intermediates in the normal process of cellular respiration. Oxidants that are free radicals have been implicated as initiators of ... a. C-reactive protein b. Serum amyloid c. a -Proteinase inhibitor d. Fibrinogen e. Albumin
Last Answer : Answer: a, b, c, d The acute-phase response is a series of homeostatic responses of the organism to tissue injury in infection and inflammation. After an inflammatory stimulus occurs, a number ... 30% to 50% of the level before injury. The reason for the decrease in production is poorly understood
Description : When radiation breaks an electron pair bond in a molecule and each fragment of the molecule gets one of the bond electrons, the molecular fragments that are formed are called: w) ions x) free radicals y) stable molecules z) gases
Last Answer : ANSWER: X -- FREE RADICALS
Description : Aromatic hydrocarbons are mainly obtained from
Last Answer : coal.
Description : Write the structure of the first member of the aromatic hydrocarbons. OR Explain the structure of benzene.
Last Answer : Benzene is the first member of the aromatic hydrocarbon series. Its molecular formula is C 6 H 6 . A benzene molecule is made up of 6 carbon atoms and 6 hydrogen atoms. Its structural formula is as shown in the figure. A benzene ring has six carbon atoms with alternate single and double bonds.
Description : What are aromatic hydrocarbons or arenes?
Last Answer : Aromatic hydrocarbons are hydrocarbons that have atleast one aromatic ring (benzene ring).
Description : Which of the following pollutants is not emitted from the transport sector? (A) Oxides of nitrogen (B) Chlorofluorocarbons (C) Carbon monoxide (D) Poly aromatic hydrocarbons
Last Answer : (B) Chlorofluorocarbons
Description : Assertion (A) : Some carbonaceous aerosols may be carcinogenic. Reason (R) : They may contain polycyclic aromatic hydrocarbons (PAHs). (A) Both (A) and (R) are correct and (R) is the correct explanation of (A). (B) Both ... (C) (A) is correct, but (R) is false. (D) (A) is false, but (R) is correct.
Last Answer : Answer: A
Description : Tobacco smoke is injurious to health because it contains : (1) Carbon monoxide (2) Nicotine (3) Polycyclic aromatic hydrocarbons (4) Melathene
Last Answer : Carbon monoxide
Description : Ethers are stored in brown bottles. This is because on exposure to air and light ethers are converted to (a) Peroxides (b) Oxonium ions (c) Ozonides (d) Electrophiles
Last Answer : Peroxides
Description : In electrophilic aromatic substitution reactions a chlorine substituent __________. (a) is a deactivator and a m-director (b) is a deactivator and an o,p-director (c) is an activator and a m-director (d) is an activator and an o,p-director
Last Answer : is a deactivator and an o,p-director
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 : Which of the following phrases is NOT appropriate for a description of benzene? w) characteristic reactivity of an alkene x) volatile liquid y) aromatic hydrocarbon z) resonance hybridization
Last Answer : ANSWER: W -- CHARACTERISTIC REACTIVITY OF AN ALKENE
Description : Why do alcohols have boiling points much higher than hydrocarbons of similar molecular weight? (a) Alcohols have greater van der Waals attraction forces. (b) Alcohol molecules have greater ... of volatilization. (d) Alcohols must overcome greater ionic forces in the process of volatilization.
Last Answer : Hydrogen bonds must be broken in the process of volatilization
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 : Which of the following statements is correct regarding nucleophiles? (a) They have an overall positive charge (b) They have a lone-pair of electrons (c) They have an unpaired electron (d) They have empty orbitals
Last Answer : (b) They have a lone-pair of electrons
Description : The compound methylamine, H3C–NH2, contains a C–N bond. In this bond, which of the following best describes the charge on the nitrogen atom? (a) slightly positive (b) uncharged (c) slightly negative (d) –1
Last Answer : slightly negative
Description : In the following compounds, anisole (I), benzene (II) and nitrobenzene (III), the ease of reaction with electrophiles is:
Last Answer : In the following compounds, anisole (I), benzene (II) and nitrobenzene (III), the ease of reaction ... . `IIIgtIIgtI` C. `IIgtIgtIII` D. `IgtIIgtIII`
Description : An aqueous solution of glycine is neutral because of the formation of : (a) Carbanion (b) Zwitterion (c) Carbonium ions (d) Free radicals
Last Answer : Zwitterion
Description : The mechanism of dehydration of an alcohol to give an ether involves formation of : (a) Carbonium ions (b) Carbanions (c) Free radicals (d) Carbenes
Last Answer : Carbonium ions
Description : The mechanism of dehydration of an alcohol to give an alkene involves formation of : (a) Carbonium ions (b) Carbanions (c) Free radicals (d) Carbenes
Description : Chlorine free radicals react with methane by : (a) donating their free-radical electron to methane to form chloromethane. (b) abstracting a hydrogen atom from methane, and producing ... produce chloromethane. (d) forming a carbonium ion intermediate that rapidly dissociates to form chloromethane
Last Answer : abstracting a hydrogen atom from methane, and producing HCl and a methyl radical
Description : In the chlorination of alkanes, the first step in which chlorine free radicals are produced is called : (a) initiation (b) activation (c) propagation (d) deactivation
Last Answer : initiation
Description : Homolytic fission of C–C bond leads to the formation of : (a) Free radicals (b) Carbonium ions (c) Carbanions (d) None of these
Description : For glyburide, all of the following metabolic reactions are logical EXCEPT (A) O-demethylation (B) aromatic oxidation (C) benzylic hydroxylation (D) amide hydrolysis
Last Answer : (B) aromatic oxidation
Description : The products resulting from the atmospheric reactions of hydrocarbons and nitrogen oxides in the presence of sunlight are called
Last Answer : The products resulting from the atmospheric reactions of hydrocarbons and nitrogen oxides in the ... C. Tertiary pollutants D. Non-pollutants
Description : Aniline point is the (A) Characteristic property of diesel & lubricating oils (B) Measure of aromatic content of oil (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B
Description : Pick out the wrong statement. (A) Molecules with symmetrical arrangements (e.g. CH4 or CCl4) are non polar (B) Generally, non-polar compounds are chemically inactive, conduct electricity poorly and do not ionise (C) Most of the hydrocarbons are non-polar (D) None of these
Last Answer : (D) None of these
Description : (A) Nucleophiles attack the regions of high electron density. (R) Nucleophiles act as Lewis bases.
Last Answer : (A) Nucleophiles attack the regions of high electron density. (R) Nucleophiles act as Lewis bases. A. If ... IF (A) is incorrect but (R) is correct.
Description : Arrange the following nucleophiles in the order of their nucleophilic strength.
Last Answer : Arrange the following nucleophiles in the order of their nucleophilic strength. A. `OH^(-)gtCH_(3)COO^(-)gtCH_(3)O^ ... (5)O^(-)ltOH^(-)ltCH_(3)O^(-)`
Description : `CH_(3)Br+Nu^(-)rarrCH_(3)Nu+Br^(-)` The decreasing order of the rate of the above reaction with nucleophiles `(Nu^(-))` A to D is : `[Nu^(-)=(A)PhO^(
Last Answer : `CH_(3)Br+Nu^(-)rarrCH_(3)Nu+Br^(-)` The decreasing order of the rate of the above reaction with nucleophiles `(Nu ... B gt C gt D D. B gt D gt C gt A
Description : Which of the following statements is not correct for a nucleophiles?
Last Answer : Which of the following statements is not correct for a nucleophiles? A. Nucleophiles are not electron ... a Lewis acid D. Ammonia is a nucleophile
Description : What are ambident nucleophiles?
Last Answer : Nucleophiles which can attack through two different sites arecalled ambident nucleophiles. For example, cyanide ion is aresonance hybrid for its structure. It can attack either throughcarbon to form cyanides or through N to form isocyanides orcarbylamines.
Description : Hydrocarbons have a characteristic odour only in
Last Answer : vapour state.
Description : Why are the planets uncharged ?
Last Answer : Answer : The planets are not uncharged but as their positive and negative charges are equal they are apparently uncharged.
Description : An uncharged capacity ER C=`100muF` with a resistor is connected with AC source as shown in the figure If R= is `50Omega` and switch S is closed at t=
Last Answer : An uncharged capacity ER C=`100muF` with a resistor is connected with AC source as shown in the figure If R ... `(v_(A)-V_9B)` is k volt. Calculate K
Description : When an uncharged object loses electrons it becomes?
Last Answer : Need answer
Description : Chymotrypsin is specific for peptide bonds containing (A) Uncharged amino acid residues (B) Acidic amino acids (C) Basic amino acid (D) Small amino acid residues
Last Answer : Answer : A
Description : An uncharged object has A. more protons B. more electrons C. equal electrons and protons D. no protons and electrons
Last Answer : equal electrons and protons
Description : Phenomena in which a charged body attract uncharged body is called A. electrostatic induction B. electric current C. charge movement D. magnetic induction
Last Answer : electrostatic induction
Description : Example of spherical system in the following is a) Charge in space b) Charge in box c) Charge in dielectric d) Uncharged system
Last Answer : a) Charge in space