What is Grignard reagent?

What is Grignard reagent?
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Ans. Alkyl magnesium halides
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Related questions

Explain why Grignard reagents do not reacts with alkanes.

Description : Explain why Grignard reagents do not reacts with alkanes.

Last Answer : Ans. In alkanes , the C – H bond has very little polarity . The hydrogen cannot be abstracted by the Grignard reagent.

Explain the physical properties of benzene and its homologues.

Description : Explain the physical properties of benzene and its homologues.

Last Answer : Ans: i. Benzene and its homologous upto eight carbon atoms are colourless liquids with characteristic smell. ii. Aromatic hydrocarbons are immiscible with water but soluble in organic solvents. iii. ... compounds increases with increase in molecular mass due to increase in van der waals forces.

Out of benzene, m–dinitrobenzene and toluene which will undergo nitration most easily and why?

Description : Out of benzene, m–dinitrobenzene and toluene which will undergo nitration most easily and why?

Last Answer : Ans. -CH3 group is electron donating while –NO2 group is electron withdrawing. Therefore, maximum electron density will be in toluene , followed by benzene and at least in m-dinitrobenzene. Therefore, the ease of nitration decreases in the order: Toluene> benzene> m-dinitrobenzene

Which one is more stable structure of benzene among Kekule and Dewar’s structures?

Description : Which one is more stable structure of benzene among Kekule and Dewar’s structures?

Last Answer : Ans: Kekule’s structure.

Define benzenoids Compounds.

Description : Define benzenoids Compounds.

Last Answer : Ans: Aromatic compounds containing benzene ring.

Define Aromatic Compounds.

Description : Define Aromatic Compounds.

Last Answer : Ans: The Compounds which gives pleasant smell.

What are alkanes? Why are they called paraffins?

Description : What are alkanes? Why are they called paraffins?

Last Answer : Ans. Those hydrocarbons which contain single bond between carbon- carbon are called alkanes. They are called paraffins because they are very less reactive (Latin- Parum= little, affins = affinity)

How will you separate propene from propyne?

Description : How will you separate propene from propyne?

Last Answer : Ans. By passing the mixture through ammonical silver nitrate solution when propyne reacts while propene passes over.

How will you demonstrate that double bonds of benzene are somewhat different from that of olefins?

Description : How will you demonstrate that double bonds of benzene are somewhat different from that of olefins?

Last Answer : Ans. The double bonds of olefins decolorize bromine water and discharge the pink colour of Bayer‘s reagent while those of benzene not.

What is meant by restricted rotation around of carbon-carbon double bond? What type of isomerism does it lead to?

Description : What is meant by restricted rotation around of carbon-carbon double bond? What type of isomerism does it lead to?

Last Answer : Ans. The carbon-carbon double bond in alkene contains one sigma bond and one pi-bond. The Pibond involves the overlapping of unhybridised p orbital of two carbon atom .The rotation around the ... , the free rotation around C=C double bond is restricted, which gives rise to Geometrical Isomerism.

How will you detect the presence of unsaturation in an organic compound?

Description : How will you detect the presence of unsaturation in an organic compound?

Last Answer : Ans. Generally Unsaturated organic compound decolorize Bayer‘s reagent and Bromine water.

Arrange the following in order of decreasing reactivity towards alkanes. HCl, HBr, HI, HF

Description : Arrange the following in order of decreasing reactivity towards alkanes. HCl, HBr, HI, HF

Last Answer : Ans. HI> HBr> HCl >HF

Name two reagents which can be used to distinguish between ethene and ethyne.

Description : Name two reagents which can be used to distinguish between ethene and ethyne.

Last Answer : Ans. Tollen‘s reagent

Out of ethylene and acetylene which is more acidic and why?

Description : Out of ethylene and acetylene which is more acidic and why?

Last Answer : Ans. Acetylene, due to greater electonegativity of the sp hybridised carbon.

Arrange the following in the increasing order of C-C bond length- C2H6 , C2H4, C2H2

Description : Arrange the following in the increasing order of C-C bond length- C2H6 , C2H4, C2H2

Last Answer : Ans. C2H2 < C2H4 < C2H6

What effect does branching of an alkane chain has on its boiling point?

Description : What effect does branching of an alkane chain has on its boiling point?

Last Answer : Ans. As branching increases, the surface area of the molecule decreases which results in a small area of contact. As a result, the Van der Waals force also decreases which can be overcome at ... lower temperature. Hence, the boiling point of an alkane chain decreases with an increase in branching.

What are the necessary conditions for any system to be aromatic?

Description : What are the necessary conditions for any system to be aromatic?

Last Answer : Ans. A compound is said to be aromatic if it satisfies the following three conditions: (i) It should have a planar structure. (ii) The π-electrons of the compound are completely delocalized in the ring. (iii)The total number ... to (4n + 2), where n = 0, 1, 2 etc. This is known as Huckel s rule.

What are the main constituent of LPG?

Description : What are the main constituent of LPG?

Last Answer : Ans. Butane and isobutane . Both these isomers can be easily liquified and hence can be conveniently transported in iron cylinder.

Is it possible to isolate pure staggered ethane or pure eclipsed ethane at room temperature? Explain .

Description : Is it possible to isolate pure staggered ethane or pure eclipsed ethane at room temperature? Explain .

Last Answer : The energy differences between staggered and eclipsed forms of ethane is just 12.55 kj mol_1 which is easily met by collisions of the molecules at room temperature. Therefore, it is not possible to isolate either pure staggered or pure eclipsed ethane at room temperature.

Which of the following has highest boiling point and why?(L-II) (a) 2 methylpentane (b) 2,3 dimethyl butane (c) 2,2 dimythylbutane

Description : Which of the following has highest boiling point and why?(L-II) (a) 2 methylpentane (b) 2,3 dimethyl butane (c) 2,2 dimythylbutane

Last Answer : Ans. As the branching increases, surface area decreases. As a result, magnitude of Vander Waals forces of attraction decreases and hence the boiling point decreases. Thus, the overall order of decreasing boiling point is: 2 methylpentane (333k) > 2,3 dimethylbutane (331k) > 2,2 dimethylbutane(323k)

Why do the C-C bonds rather than C-H bonds break during cracking of alkanes?

Description : Why do the C-C bonds rather than C-H bonds break during cracking of alkanes?

Last Answer : Ans. Since the bond dissociation energy of C-C bonds (348kj /mol) is lower than bond dissociation energy of C-H bonds (414kj/mol), therefore, during cracking of alkanes, C-C bonds break more early than C-H bonds.

(a) What effect the branching of an alkane has on its melting point? (L-III) (b) Which of the following has highest boiling point?(L-III) (1) 2-methyl pentane. (2) 2, 3-diethyl butane. (3) 2, 2- dimethyl butane.

Description : (a) What effect the branching of an alkane has on its melting point? (L-III) (b) Which of the following has highest boiling point?(L-III) (1) 2-methyl pentane. (2) 2, 3-diethyl butane. (3) 2, 2- dimethyl butane.

Last Answer : Ans.(a) In general conception, as the branching increases packing of the molecules in the crystals becomes less close and have melting point decreases accordingly. (b) As the branching increases, ... attraction decreases and hence the boiling point decreases. So, 2-methyl pentane has highest B.pt.

Arrange the three isomers of pentane in increasing order of their boiling points?

Description : Arrange the three isomers of pentane in increasing order of their boiling points?

Last Answer : Ans.2, 2-Dimethylpropane

What do you mean by pyrolysis?

Description : What do you mean by pyrolysis?

Last Answer : The decomposition of a compound by the heat is called pyrolysis. This process when applied to alkanes is known as cracking.

Why are alkanes called paraffins?

Description : Why are alkanes called paraffins?

Last Answer : Paraffin’s means little affinity; alkanes due to strong C-C and C-H bonds are relatively chemically inert.

What are conformations?

Description : What are conformations?

Last Answer : Conformations are spatial arrangements which are obtained by rotation around sigma bonds.

Which reaction does not yield an ester as one of the products?(a) A carboxylic acid is heated with an alcohol (b) A Grignard reagent is added to a carboxylic acid (c) An acid halide is treated with an alcohol (d) An alkyl halide is heated with the salt of a carboxylic acid

Description : Which reaction does not yield an ester as one of the products? (a) A carboxylic acid is heated with an alcohol (b) A Grignard reagent is added to a carboxylic acid (c) An acid halide is treated with an alcohol (d) An alkyl halide is heated with the salt of a carboxylic acid

Last Answer : A Grignard reagent is added to a carboxylic acid

Which of the following reagents will react readily with both aldehydes and ketones? (a) Grignard reagent (b) Fehling's reagent (c) Tollens' reagent (d) Schiff's reagen

Description : Which of the following reagents will react readily with both aldehydes and ketones? (a) Grignard reagent (b) Fehling's reagent (c) Tollens' reagent (d) Schiff's reagen

Last Answer : Grignard reagent

Which of the following alcohols can be prepared by the reaction of methyl formate with excess Grignard reagent? (a) 1-pentanol (b) 2-pentanol (c) 3-pentanol (d) 2-methyl-2-pentanol

Description : Which of the following alcohols can be prepared by the reaction of methyl formate with excess Grignard reagent? (a) 1-pentanol (b) 2-pentanol (c) 3-pentanol (d) 2-methyl-2-pentanol

Last Answer : 3-pentanol

Which of the following is correct? (a) When a Grignard reagent reacts with a ketone, the addition product is a primary alcohol. (b) When a Grignard reagent reacts with a ketone, the addition product is a secondaryalcoho(c) When a Grignard reagent reacts with a aldehyde, the addition product is a tertiary alcohol. (d) None of the above are correct.l

Description : Which of the following is correct? (a) When a Grignard reagent reacts with a ketone, the addition product is a primary alcohol. (b) When a Grignard reagent reacts with a ketone, the addition product ... with a aldehyde, the addition product is a tertiary alcohol. (d) None of the above are correct.

Last Answer : None of the above are correct.

Grignard reagent is chemically known as (A) Ethyl magnesium chloride (B) Methyl magnesium chloride (C) Dichlorophenol (D) Monochloroacetic acid

Description : Grignard reagent is chemically known as (A) Ethyl magnesium chloride (B) Methyl magnesium chloride (C) Dichlorophenol (D) Monochloroacetic acid

Last Answer : (A) Ethyl magnesium chloride

Chemical name of Grignard reagent is (A) Sodium thiosulphate (B) Ethyl magnesium chloride (C) Sodium sulphite (D) Sodium bicarbonate

Description : Chemical name of Grignard reagent is (A) Sodium thiosulphate (B) Ethyl magnesium chloride (C) Sodium sulphite (D) Sodium bicarbonate

Last Answer : (B) Ethyl magnesium chloride

Why are Grignard reagents soluble in ether but not in benzene ?

Description : Why are Grignard reagents soluble in ether but not in benzene ? 

Last Answer : Ans. Grignard reagents from co-ordination complexes with ether but not benzene since the former has lone pair of electrons but the later does not.

Ketones react with Grignard reagents to form an addition product which on hydrolysis gives a (a) Primary alcohol (b) Tertiary alcohol (c) Secondary alcohol (d) Ketal

Description : Ketones react with Grignard reagents to form an addition product which on hydrolysis gives a (a) Primary alcohol (b) Tertiary alcohol (c) Secondary alcohol (d) Ketal

Last Answer : Tertiary alcohol

Grignard reagents do not show any reaction with (a) Alkoxyalkanes (b) Alkanones (c) Alkyl alkanoates (d) Acyl halides

Description : Grignard reagents do not show any reaction with (a) Alkoxyalkanes (b) Alkanones (c) Alkyl alkanoates (d) Acyl halides

Last Answer : Alkoxyalkanes

The disappearance of the purple color of KMnO4 in its reaction with alkene is known as (a) Markovnikov test (b) Grignard test (c) Baeyer test (d) Wurtz test

Description : The disappearance of the purple color of KMnO4 in its reaction with alkene is known as (a) Markovnikov test (b) Grignard test (c) Baeyer test (d) Wurtz test

Last Answer : Baeyer test

Whose name is given to alkylmagnesium halides: w) Victor Grignard x) Daniel Rutherford y) Dmitri Mendeleev

Description : Whose name is given to alkylmagnesium halides: w) Victor Grignard x) Daniel Rutherford y) Dmitri Mendeleev

Last Answer : ANSWER: W -- VICTOR GRIGNARD

The modern atomic theory was conceived by : w) Victor Grignard x) Daniel Rutherford y) Svante Arrhenius z) John Dalton

Description : The modern atomic theory was conceived by : w) Victor Grignard x) Daniel Rutherford y) Svante Arrhenius z) John Dalton

Last Answer : ANSWER: Z -- JOHN DALTON

What is Lucas Reagent ?

Description : What is Lucas Reagent ?

Last Answer : : A mixture of concentrated HCl and insoluble ZnCl2 is called Lucas reagent.

What is a limiting reagent ?

Description : What is a limiting reagent ?

Last Answer : In a reaction, the number of molecules that do not remain in the reactant is called limiting reactant.

Alcoholic OH) group can be identified by : (1) Tolien's Reagent Test (2) Esterification Test (3) FeCl3 Test (4) Ozonolysis Reaction

Description : Alcoholic OH) group can be identified by : (1) Tolien's Reagent Test (2) Esterification Test (3) FeCl3 Test (4) Ozonolysis Reaction

Last Answer : (3) FeCl3 Test Explanation: As phenol is an aromatic alcohol, so FeCl3 test is a test for alcohol and esterificaton test is also a test for alcohol. The ferric chloride test is used to determine the presence or absence of phenols in a given sample (for instance natural phenols in a plant extract).

Write the name of reagent use for initating a free radical chain reaction.

Description : Write the name of reagent use for initating a free radical chain reaction. 

Last Answer : Ans: Tertiary Butyle peroxaide. 

Benzaldehyde does not react with (a) Tollens' reagent (b) Phenylhydrazine (c) Fehling's solution (d) NaHSO3

Description : Benzaldehyde does not react with (a) Tollens' reagent (b) Phenylhydrazine (c) Fehling's solution (d) NaHSO3

Last Answer : Fehling's solution

Benzaldehyde can be distinguished from acetophenone by using : (a) Tollens' reagent (b) Lucas reagent (c) Fehling's reagent (d) All of these

Description : Benzaldehyde can be distinguished from acetophenone by using : (a) Tollens' reagent (b) Lucas reagent (c) Fehling's reagent (d) All of these

Last Answer : Tollens' reagent

The reagent that can be used to differentiate an aldose and a ketose is : (a) Bromine water (b) Fehling's solution (c) Tollens' reagent (d) None of these

Description : The reagent that can be used to differentiate an aldose and a ketose is : (a) Bromine water (b) Fehling's solution (c) Tollens' reagent (d) None of these

Last Answer : Bromine water

Which of the following compounds reduces Tollens' reagent? (a) Glucose (b) Sucrose (c) Methanol (d) Acetic acid

Description : Which of the following compounds reduces Tollens' reagent? (a) Glucose (b) Sucrose (c) Methanol (d) Acetic acid

Last Answer : Glucose

Which of the following statements is false about sucrose? (a) It is also called table sugar. (b) It may be fermented by yeast to produce alcohol. (c) It reduces Fehling's solution. (d) It does not reduce Tollens' reagent.

Description : Which of the following statements is false about sucrose? (a) It is also called table sugar. (b) It may be fermented by yeast to produce alcohol. (c) It reduces Fehling's solution. (d) It does not reduce Tollens' reagent.

Last Answer : It reduces Fehling's solution

Which of the following compounds will dissolve in aqueous NaOH after undergoing reaction with Hinsberg reagent? (a) CH3CH2NH2 (b) (CH3CH2)2NH (c) (CH3CH2)3N (d) (CH3)3N

Description : Which of the following compounds will dissolve in aqueous NaOH after undergoing reaction with Hinsberg reagent? (a) CH3CH2NH2 (b) (CH3CH2)2NH (c) (CH3CH2)3N (d) (CH3)3N

Last Answer : CH3CH2NH2

Hinsberg's reagent is (a) Pd + BaSO4 (b) p-Toluenesulfonic acid (c) NH2NH2 + KOH (d) Benzenesulfonic acid

Description : Hinsberg's reagent is (a) Pd + BaSO4 (b) p-Toluenesulfonic acid (c) NH2NH2 + KOH (d) Benzenesulfonic acid

Last Answer : Benzenesulfonic acid