In the addition of hydrogen bromide to alkynes, which of the following
species is believed to be an intermediate?
(a) vinyl anion
(b) vinyl cation
(c) vinyl radical
(d) carbene

1 Answer

Answer :

vinyl cation

Related questions

Description : While conducting Luminol test, luminol reacts with hydrogen salt and forms: (a) Di-anion (b) Cation (c) Anion (d) All of the above

Last Answer : Ans: (a). Di-anion

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 : (a) Show on a diagram the transfer of electrons between the atoms in the formation of MgO. Write symbols of cation and anion present in MgO. (b) Name the solvent in which ionic compounds are generally soluble. (c) Why are aqueous solutions of ionic compounds able to conduct electricity? -Chemistry

Last Answer : (b) Ionic compounds are soluble in water. (c) It is because aqueous solutions consist of ions which can move freely in them and carry current.

Description : The element absorbed both in cation and anion form is – (1) Sulphur (2) Nitrogen (3) Calcium (4) Phosphorus

Last Answer : (2) Nitrogen Explanation: Nitrogen, required in large quantities for healthy plant growth, is supplied either as a cation (ammonium) or an anion (nitrate). The ratio of these two forms of nitrogen in the nutrient solution can have large effects on both the rate and direction of pH changes with time.

Description : Which of the following is aromatic? (a) cyclopentadienyl cation (b) 1,3-cyclohexadiene (c) cyclobutenyl anion (d) cycloheptatrienyl cation

Last Answer : cycloheptatrienyl cation

Description : The element absorbed both in cation and anion form is (1) Sulphur (2) Nitrogen (3) Calcium (4) Phosphorus 

Last Answer : Nitrogen

Description : Which of the following statements correctly describes the general reactivity of alkynes? (a) An alkyne is an electron-rich molecule and therefore reacts as a nucleophile. (b) The σ bonds ... fail to undergo electrophilic addition reactions. (d) Alkynes are generally more reactive than alkenes.

Last Answer : Alkynes are generally more reactive than alkenes.

Description : What is the difference between a cation and an anion?

Last Answer : A cation is a positively charged ion, while an anion is a negatively charged ion.

Description : What is the difference between a cation and an anion?

Last Answer : A: A cation is a positively charged ion, while an anion is a negatively charged ion.

Description : What is the difference between cation and anion? -Chemistry 9th

Last Answer : Cations and anions introduction: Ions which are a part of the science subject Chemistry forms from atoms and electrons that have either gained or lost their weight by the removal or adding of one or more ... of electrons is more than the number of protons in an anion. thank you hope this helps u

Description : A cation and an anion slowly move towards each other. What happens to the strength of the electrostatic force between them?

Last Answer : The Strength is increased and and Ionic bond is formed.An Ionic bonds involve a cation and an anion. The bond is formed when an atom, typically a metal, loses an electron or electrons, and ... it. The ions produced are oppositely charged and are attracted to one another due to electrostatic forces.

Description : Is gallium a cation or anion?

Last Answer : Gallium is a metallic element. It forms cations Ga3+ and Ga+

Description : Is boron a cation or a anion?

Last Answer : Boron is an element and is neither an anion or cation. Ifionized it would tend to from B3+ and would be thus a cation.

Description : What is beryllium cation or anion?

Last Answer : Beryllium cation is Be(2+).

Description : Is calcium an cation or anion?

Last Answer : Calcium has the cation Ca(2+).

Description : Is calcium an cation or anion?

Last Answer : Calcium has the cation Ca(2+).

Description : What is beryllium cation or anion?

Last Answer : Beryllium cation is Be(2+).

Description : At a pH below the isoelectric point, an amino acid exists as (A) Cation (B) Anion (C) Zwitterion (D) Undissociated molecule

Last Answer : Answer : A

Description : At isoelectric pH, an amino acid exists as (A) Anion (B) Cation (C) Zwitterion (D) None of these

Last Answer : Answer : C

Description : Polyvinyl alcohol is used as a (A) Cation/anion exchanger (B) Water soluble adhesive (C) Textile fibre (D) Non-sticky coating on frying pans

Last Answer : (B) Water soluble adhesive

Description : Permanent hardness of water can be removed by (A) Simply boiling (B) Adding alum (C) Passing it through cation & anion exchangers (D) All (A), (B) and (C)

Last Answer : (C) Passing it through cation & anion exchangers

Description : Which of the following electrolytes is a major anion in body fluid? a) Chloride Chloride is a major anion found in extracellular fluid. b) Potassium Potassium is a cation. c) Sodium Sodium is a cation. d) Calcium Calcium is a cation.

Last Answer : a) Chloride Chloride is a major anion found in extracellular fluid.

Description : Which of the following electrolytes is a major cation in body fluid? a) Potassium Potassium is a major cation that affects cardiac muscle functioning. b) Chloride Chloride is an anion. c) Bicarbonate Bicarbonate is an anion. d) Phosphate Phosphate is an anion.

Last Answer : a) Potassium Potassium is a major cation that affects cardiac muscle functioning.

Description : In solid-state optical detectors, the excited charge is transported in the solid by ∙ a. Holes and protons ∙ b. Holes and electrons ∙ c. Anion and cation ∙ d. Protons and photons

Last Answer : ∙ b. Holes and electrons

Description : What is the cation for Tin IV Bromide?

Last Answer : Need answer

Description : Propene reacts with HBr in the presence of a peroxide to give (a) n-Propyl bromide (b) Allyl bromide (c) Isopropyl bromide (d) Vinyl bromide

Last Answer : n-Propyl bromide

Description : A family of organic compounds containing only carb and hydrogen and having only single bonds are the: w) alkenes and alkanes x) alkanes and cycloalkanes y) alkynes (pron: AL-kines) and alkenes z) cycloalkanes and alkenes

Last Answer : ANSWER: B -- ALKANES AND CYCLOALKANES

Description : Give reason: Alkanes undergo only substitution reactions but alkenes and alkynes undergo both substitution and addition reactions.

Last Answer : Alkenes and alkynes have double and triple bonds, which on breaking can add hydrogen atoms to satisfy the valency.

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 : Who am i I was a publisher whose abolitionist views were radical even in the north. I believed in civil disobedience and many abolitionists disagreed with my views about equality for women?

Last Answer : William Lloyd Garrison

Description : Phenylmagnesium bromide reacts with acetaldehyde to form an addition product which undergoes acid-hydrolysis to give (a) Diphenylcarbinol (b) Benzyl alcohol (c) Methylphenylcarbinol (d) Benzoic acid

Last Answer : Methylphenylcarbinol

Description : Which of the following characterizes the reactions of aldehydes and ketones? (a) electrophilic addition (b) electrophilic substitution (c) nucleophilic acyl substitution (d) nucleophilic addition; free radical addition

Last Answer : nucleophilic addition; free radical addition

Description : The chlorination of methane to give CCl4 is an example of (a) an electrophilic addition (b) a free-radical substitution (c) a nucleophilic addition (d) an electrophilic substitution

Last Answer : a free-radical substitution

Description : Which of the following statements describes the first step in the mechanism of the aldol condensation? (a) An alpha hydrogen is abstracted by the base to form an enolate anion. (b) A nucleophilic base attacks ... by the base ion. (d) The alpha hydrogen is abstracted by an acid to the enolate anion.

Last Answer : An alpha hydrogen is abstracted by the base to form an enolate anion

Description : Which of the following statements are true of oxidants? A. In addition to their pathophysiologic roles in inflammation, injury, and infection, oxidants also have physiologic roles. B. Oxidants may ... involved the catalytic production of superoxide anion (O 2 ) by the enzyme xanthine oxidase.

Last Answer : Answer: ABCD DISCUSSION: Oxidants are reactive oxygen metabolites that have both physiologic and pathophysiologic roles. As potent oxidizing agents, oxidants are involved in cytochrome P ... leukocyte infiltration and activation, causing further tissue damage by the release of cytotoxic proteases

Description : What is the name given for a species that contains a positively charged carbon atom? (a) carbanion (b) carbocation (c) methyl radical (d) free radical

Last Answer : carbanion

Description : Which of the following forms the weakest acid in aqueous solution? w) hydrogen fluoride x) hydrogen chloride y) hydrogen bromide z) hydrogen iodide

Last Answer : ANSWER: W -- HYDROGEN FLUORIDE

Description : Which of the following substances would be expecte to have the highest melting point? w) Potassium Bromide x) Iodine y) Methane z) Hydrogen Chloride

Last Answer : ANSWER: W -- POTASSIUM BROMIDE

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 : 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 : Which of the following is not a correct statement about the electrophilic substitution mechanism of benzene? (a) Benzene functions as a nucleophile. (b) Formation of a carbocation intermediate is the ... hybridized carbon in the ring. (d) The addition product is a frequently observed minor product.

Last Answer : The addition product is a frequently observed minor product.

Description : Why do aldehydes undergo nucleophilic addition reactions while esters undergo nucleophilic acyl substitution reactions? (a) The carbonyl carbon of an ester is more electrophilic than that of an aldehyde. (b) ... adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic

Last Answer : Once the nucleophile adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic

Description : How do you define free radical addition reaction ?

Last Answer : Give an example. When unsaturated compounds undergo addition reactions with free radicals, it is called free radical addition reaction. Ex; CH3-CH = CH2+HBr-----------> CH3-CH2-CH2Br

Description : Addition polymerisation takes place either by a free radical mechanism or ionic mechanism depending on the reagents used. Free radical polymerisation is catalyzed by __________, which decompose to give free radicals. (A) Organic peroxides (B) Sulphuric acid (C) Hydrofluoric acid (D) None of these

Last Answer : (A) Organic peroxides

Description : It is believed that carbon-14 in nature is slowly generated by the action of: w) protons on carbon-12 x) electrons on hydrogen y) cosmic rays on boron z) neutrons on nitrogen

Last Answer : ANSWER: Z -- NEUTRONS ON NITROGEN 

Description : Alkali metal hydrogen fluorides have a formula `M[HF_2]`. They are found to contain a linear symmetrical anion having an overall F—H—F distance of 2.2

Last Answer : Alkali metal hydrogen fluorides have a formula `M[HF_2]`. They are found to contain a linear symmetrical ... F-atoms through two T bonds in the anion.

Description : All the following statements about renal tubular acidosis are correct except (A) Renal tubules may be unable to reabsorb bicarbonate (B) Renal tubules may be unable to secrete hydrogen ions (C) Plasma chloride is elevated (D) Anion gap is decreased

Last Answer : Answer : D

Description : Saturated hydrocarbons are called - (1) Alkynes (2) Alkenes (3) Alkanes (4) All of the above

Last Answer : (3) Alkanes Explanation: Carbon compounds which contain just carbon and hydrogen are called hydrocarbons. Among these, the saturated hydrocarbons are called alkanes. The unsaturated hydrocarbons which contain one or more double bonds are called alkenes.

Description : Cycloalkanes have the same molecular formula as : (a) Alkanes (b) Alkenes (c) Alkynes (d) Cycloalkenes

Last Answer : Alkenes