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All questions of Hydrocarbon Isomers for Grade 9 Exam

Which among the following defines Meso forms of isomers?
  • a)
    Meso form is optically inactive due to external compensation.
  • b)
    The molecules of the meso isomers are chiral.
  • c)
    It can be separated into optically active enantiomeric pairs.
  • d)
    It is a single compound.
Correct answer is option 'D'. Can you explain this answer?

Rohan Singh answered
Meso forms of isomers are single compounds and their molecules are achiral hence they cannot be separated into pairs.
Additional Information: A meso compound or meso isomer is a non-optically active member of a set of stereoisomers, at least two of which are optically active. This means that despite containing two or more stereogenic centers, the molecule is not chiral. 

If chlorocyclohexane is subjected to further chlorination, how many different isomers (geometrical plus structural only) of dichiorocyclohexane would be produced? 
  • a)
    3
  • b)
    5
  • c)
    6
  • d)
    7
Correct answer is option 'D'. Can you explain this answer?

The correct answer is option D
There will be three constitutional isomers i.e. 1,2 dichloro cyclohexane,1,3 dichloro cyclohexane and1,4 dichloro cyclohexane.Each constitutional isomer will have cis and trans configuration thereby making six isomers in all.Also there will be two optically active isomers.
You can understand it better through these infographics
1,2 dichloro cyclohexane

  • a)
    3
  • b)
    4
  • c)
    5
  • d)
    6
Correct answer is option 'D'. Can you explain this answer?

Krishna Iyer answered
General formula of ketone = CnH2nO
12x+2x+16 = 100
x = 6
So, the formula of compound is C6H12O. We have to make ketone only. These are as follow

  • a)
    3
  • b)
    4
  • c)
    5
  • d)
    7
Correct answer is option 'A'. Can you explain this answer?

Riya Banerjee answered
The compounds with each doubly bonded carbon attached to two different groups (like Cab=Cab, Cab=Ccd) exhibit geometrical isomerism i.e., cis and trans forms. The geometrical isomerism arises due to restricted rotation of double bond.
However, even though there is restricted rotation for triple bond, alkynes do not exhibit geometrical isomerism, since the triply bonded carbons are attached to one group each only.

 The observed order of the stability of the cabocation is:
  • a)
    (CH3)2CH+ < (CH3)3C+ 3+ < CH3CH2+
  • b)
    CH3+ < CH3CH2+ <(CH3)2CH+ < (CH3)3C+
  • c)
    CH3CH2+ <(CH3)2CH+ < (CH3)3C+ < CH3+
  • d)
    CH3+ < CH3CH2+ < (CH3)3C+ <(CH3)2CH+
Correct answer is option 'B'. Can you explain this answer?

Rajesh Gupta answered
Alkyl groups directly attached to the +vely charged carbon stabilize the carbocations due to inductive and hyperconjugation effects.
Inductive effect:
→ Stability of carbocation 
→ More number of +I group more stable carbocation.

Hyperconjugation:
Stability 
∝Number of canonical structures
              ∝Number of H (alpha hydrogen)

  • a)
    3
  • b)
    5
  • c)
    7
  • d)
    8
Correct answer is option 'C'. Can you explain this answer?

Neha Joshi answered
The correct answer is Option B.
 
5 isomers are possible. C5H10(CnH2n). Molecules having the CnH2n formulas are most likely to be cyclic alkanes. The five isomers are:

(1)   Cyclopentane 
(2) 1-Methylcyclobutane  
(3) 1-Ethylcyclopropane 
(4) 1,1-Dimethylcyclopropane 
(5) 1,2-Dimethylcyclopropane
 

Consider all possible isomeric ketones, including stereoisomers of Molecular weight 100. All these isomers are independently reacted with NaBH4
(Note stereoisomers are also reacted separately). The total number of ketones that give a racemic product(s) is/are
 
[JEE Advanced 2014] 
  • a)
    3
  • b)
    4
  • c)
    5
  • d)
    6
Correct answer is option 'C'. Can you explain this answer?

Pooja Shah answered
The general formula of isomeric ketone having molecular mass 100 is C6​H12​O [6×12+12×1+16].
The possible structure will be :
 
The number of ketones that gives racemic mixture with NaBH4​ is 5 as the ketone with chiral center will give diastereoisomer with NaBH4​

The isomer of ethanol is:
  • a)
    Dimethyl ether 
  • b)
    Diethyl ether  
  • c)
    Methanol
  • d)
    Acetone
Correct answer is option 'A'. Can you explain this answer?

The isomer of ethanol(CH3-CH2-OH) is dimethyl ether(CH3-O-CH3). This is a functional isomer of ethanol.
Explanation:
  • Functional isomers are the ones with the same molecular formula but different functional groups.
  • The molecular formula for dimethyl ether is C2H6O similar to ethanol.
  • Dimethyl ether has the structural formula CH3OCH3 and ethanol has the structural formula CH3CH2OH.
  • Therefore, dimethyl ether is the functional isomer of ethanol as both have the same molecular formula but one is ether and the other is alcohol. 

[JEE Main 2014 Online Exam]
  • a)
    a
  • b)
    b
  • c)
    c
  • d)
    d
Correct answer is option 'B'. Can you explain this answer?

The correct answer is option 'B' - sp2 and sp.

Explanation:
In allene (C3H4), there are two carbon atoms, each with three sigma bonds. To determine the hybridization of the carbon atoms, we need to look at their bonding and lone pairs of electrons.

1. Hybridization of the first carbon atom:
- The first carbon atom is bonded to two other carbon atoms and one hydrogen atom.
- It has three sigma bonds, which means it will have three hybrid orbitals.
- The carbon atom also has one lone pair of electrons.
- The presence of three sigma bonds and one lone pair indicates sp2 hybridization.
- Therefore, the first carbon atom is sp2 hybridized.

2. Hybridization of the second carbon atom:
- The second carbon atom is also bonded to two other carbon atoms and one hydrogen atom.
- It also has three sigma bonds, which means it will have three hybrid orbitals.
- The carbon atom does not have any lone pairs of electrons.
- The presence of only three sigma bonds indicates sp hybridization.
- Therefore, the second carbon atom is sp hybridized.

In summary, in allene (C3H4), the type of hybridization of the carbon atoms is sp2 and sp.

A pair of enantiomers is possible for _______ isomer of 2,2-dibromobicyclo [2.2.1] heptane.
  • a)
    cis
  • b)
    trans
  • c)
    both cis and trans
  • d)
    none of the above
Correct answer is option 'A'. Can you explain this answer?

Tejas Verma answered
Only one pair of enantiomers is possible for cis-2,2-dibromobicyclo [2.2.1] heptane. The trans arrangement of one carbon bridge is structurally impossible. Such a molecule would have too much strain.

How many structural isomers are possible with molecular formula C4H10O ?
  • a)
    3
  • b)
    5
  • c)
    7
  • d)
    8
Correct answer is option 'C'. Can you explain this answer?

Preeti Iyer answered
The formula that these isomers contain no rings or double bonds. The isomers must be alcohols and ethers.

Let's start by drawing the alcohols.
Start with four carbons in a row and put an  OH  group in every possible position.

This gives us

1. CH3CH2CH2CH2OH, butan 1-ol

and

2. CH3CH2CH(OH)CH3, butan-2-ol

Now use a 3-carbon chain with a CH3 on the middle carbon.

This gives
(CH3)2CHCH2OH, 2-methylpropan-1-ol

and

(CH3)3COH, 2-methylpropan-2-ol.

Now for the ethers.
Let's start with five atoms in a row.
This gives

CH3CH2CH2OCH3, 1-methoxypropane

and

CH3CH2OCH2CH3 , ethoxyethane

Finally, the only choice for a branched-chain ether is

(CH3)2CHOCH3 , 2-methoxpropane.

And there are your seven isomers of C4H10O.

 Heterolytic cleavage is a way to cleave the:
  • a)
    Non-ionic bonds
  • b)
    Ionic bonds
  • c)
    Covalent bonds
  • d)
    Polar bonds
Correct answer is option 'C'. Can you explain this answer?

Rahul Bansal answered
In heterolytic cleavage, a covalent bond breaks in such a way that one fragment gets both of the shared electrons. In homolytic cleavage, a covalent bond breaks in such a way that each fragment gets one of the shared electrons. The word heterolytic comes from the Greek heteros, "different", and lysis, "loosening".

C3H6O represents an aldehyde and a ketone, is a type of:
  • a)
    Chain isomerism
  • b)
    Functional group isomerism
  • c)
    Metamerism
  • d)
    Position isomerism
Correct answer is option 'B'. Can you explain this answer?

Preeti Iyer answered
The aldehyde and ketone that can be represented by molecular formula C3​H6​are propanal and propanone respectively.
Aldehyde - Propanal - CH3​CH2​CHO
Ketone - Propanone - CH3​COCH3​
These two carbon compounds are called functional isomers. They do not have the same physical properties since their functional group is different.
When hydrogen is present on one side of C=O group and other side is R, (RCHO), then it is an aldehyde group. When R is present on both sides of C=O group, then it is a ketone.

Which compound below is capable of showing geometrical isomerism ?
  • a)
    CH3 - CH = C = CH - CH3
  • b)
    CH3 - CH = C = C = CH - CH3
  • c)
  • d)
Correct answer is option 'B'. Can you explain this answer?

The correct answer is option B
CH3 – CH = C = C = CH – CH3 will show geometrical isomerism because it is odd cumulene (3 pie bond) and odd cumulene always shows geometrical isomerism 

Which of the following statements are correct?
I. A pair of positional isomers differs in the position of the same functional group.
II. A pair of. structural isomers have the same relative molar mass.
Ill. A pair of functional group isomers belongs to different homologous series. 
  • a)
    I, II and Ill 
  • b)
    I and Ill
  • c)
    II and III
  • d)
    I and II 
Correct answer is option 'A'. Can you explain this answer?

Preeti Iyer answered
According to me all statements are correct. For statement I, positional isomers have the same functional group. They just differ in the position of that group.
Statenmen II- Structural isomers have the same relative molar mass. Actually relative mass means the mass of one isomer is samee relative to another. Structural isomers differ in the structure of molecules. However they have the same molecular formula and hence; same molar mass.
Statement III- According to me, this statement is correct. As homologous series must contain the same functional group with the same physical & chemical properties. Also functional group isomers differ in the functional group attached with them. So, functional group isomers belong to different homologous series. ​

Which among the following is not an aromatic compound(in specific)
  • a)
    Naphthalene
  • b)
    Aniline
  • c)
    Pyridine
  • d)
    Tropolone
Correct answer is option 'C'. Can you explain this answer?

Sai Mishra answered
Pyridine is heterocyclic aromatic compound. Whereas naphthalene and aniline are benzenoid aromatic compounds and tropolone is a non-benzenoid aromatic compound.

How many different isomers of alkene with molecular formula C7H14, on catalytic hydrogenation, can give 3-methyl hexane? 
    Correct answer is '9'. Can you explain this answer?

    Explanation:

    Isomers are compounds with the same molecular formula but different arrangements of atoms in space. In this case, we are looking for isomers of an alkene with the molecular formula C7H14 that can give 3-methyl hexane on catalytic hydrogenation.

    Step 1: Draw the structural formula of 3-methyl hexane

    3-methyl hexane has the structural formula:


    Step 2: Draw the structural formula of the alkene

    The alkene has the molecular formula C7H14, which means it has two fewer hydrogen atoms than 3-methyl hexane. Therefore, we can start by drawing all the possible ways to add a double bond to a chain of seven carbon atoms.


    Step 3: Identify the isomers that can give 3-methyl hexane on catalytic hydrogenation

    We can now check each of these isomers to see if they can give 3-methyl hexane on catalytic hydrogenation. If an isomer can give 3-methyl hexane, it means that it has a methyl group (CH3) attached to the third carbon atom from the double bond.


    • Isomer 1: This isomer cannot give 3-methyl hexane on catalytic hydrogenation because it does not have a methyl group attached to the third carbon atom from the double bond.

    • Isomer 2: This isomer can give 3-methyl hexane on catalytic hydrogenation because it has a methyl group attached to the third carbon atom from the double bond.

    • Isomer 3: This isomer cannot give 3-methyl hexane on catalytic hydrogenation because it does not have a methyl group attached to the third carbon atom from the double bond.

    • Isomer 4: This isomer can give 3-methyl hexane on catalytic hydrogenation because it has a methyl group attached to the third carbon atom from the double bond.

    • Isomer 5: This isomer cannot give 3-methyl hexane on catalytic hydrogenation because it does not have a methyl group attached to the third carbon atom from the double bond.

    • Isomer 6: This isomer can give 3-methyl hexane on catalytic hydrogenation because it has a methyl group attached to the third carbon atom from the double bond.

    • Isomer 7: This isomer cannot give 3-methyl hexane on catalytic hydrogenation because it does not have a methyl group attached to the third carbon atom from the double bond.

    • Isomer 8: This isomer can give 3-methyl hexane on catalytic hydrogenation because it has a methyl group attached to the third carbon atom from the double bond.

    • Isomer 9: This isomer can

    Which of the following are not functional isomers of each other?
    • a)
      CH3​CH2​NO2​ and CH3​CH2​ON=O
    • b)
      C2​H5​CHO and CH3​COCH3​
    • c)
      CH3​CH2​NH2​ and CH3​NHCH3​
    • d)
      C3​H7​NH2​ and (CH3​)2​CHNH2​
    Correct answer is option 'D'. Can you explain this answer?

    Anjali Sharma answered
    Functional isomers are structural isomers that have the same molecular formula (that is, the same number of atoms of the same elements), but the atoms are connected in different ways so that the groupings are dissimilar or different functional groups.
    10 amine to different 10 amines are not functional isomers. 
    Hence, option ′d′ is the answer.
     

    How many geometrical isomers exist for the molecule shown below ?
    • a)
      2
    • b)
      3
    • c)
      5
    • d)
      6
    Correct answer is option 'B'. Can you explain this answer?

    EduRev JEE answered
    The correct answer is option B
     
    Threegeometrical isomers exits of the molecule given cis-cis, tran-trans and cis-trans.

    Organic compounds are broadly classified as
    • a)
      alicyclic compounds and acyclic compounds
    • b)
      Open chain compounds and linear chain compounds
    • c)
      Cyclic compounds and alicyclic compounds
    • d)
      Open chain compounds and closed compounds
    Correct answer is option 'D'. Can you explain this answer?

    Arpita Nambiar answered
    The correct answer is option D
    Organic compounds are broadly classified into open chain and closed chain compounds. Explanation: open chain compounds or acyclic compounds are otherwise called as aliphatic compounds.

    The number of isomers of C6H14 is:
    • a)
      4
    • b)
      5
    • c)
      6
    • d)
      7
    Correct answer is option 'B'. Can you explain this answer?

    Anu Mukherjee answered
    **Explanation:**

    To determine the number of isomers of C6H14, we need to consider the different ways in which carbon atoms can be arranged and the different ways in which hydrogen atoms can be distributed among these carbon atoms.

    **1. Straight-chain isomers:**
    The simplest isomer is the straight chain, where the carbon atoms are arranged in a linear sequence. For C6H14, there is only one straight-chain isomer.

    **2. Branched-chain isomers:**
    In branched-chain isomers, the carbon atoms are arranged in a branched manner. To determine the number of possible branched-chain isomers, we need to consider the different ways in which the branches can be arranged and the different positions at which the branches can be attached to the main chain.

    In this case, one of the carbons in the straight chain can have three branches attached to it. We can have three different arrangements of these branches, which are:

    - One branch attached to the first carbon and two branches attached to the second carbon.
    - Two branches attached to the first carbon and one branch attached to the second carbon.
    - Three branches attached to the first carbon and no branches attached to the second carbon.

    For each of these arrangements, there are different possibilities for the positions of the branches along the main chain. Therefore, for the branched-chain isomers, there are a total of three possibilities.

    **3. Cycloalkane isomers:**
    Cycloalkanes are ring structures where the carbon atoms are arranged in a closed loop. For C6H14, we can have cycloalkane isomers with different ring sizes.

    - Cyclohexane: In this case, all six carbon atoms form a single ring. There is only one possibility.

    - Cyclopentane: In this case, five carbon atoms form a ring and the remaining carbon atom is attached to one of the carbons in the ring. There is only one possibility.

    Therefore, the total number of isomers of C6H14 is the sum of the straight-chain isomer, branched-chain isomers, and cycloalkane isomers, which is 1 + 3 + 2 = 6.

    Therefore, the correct answer is option **c) 6**.

    Direction (Q. Nos. 1-18) This section contains 18 multiple choice questions. Each question has four
     choices (a), (b), (c) and (d), out of which ONLY ONE option is correct.
    Q.

    • a)
      3
    • b)
      5
    • c)
      6
    • d)
      7
    Correct answer is option 'B'. Can you explain this answer?

    Naina Sharma answered
    CH10

     Two times double bond can’t appear as it has asked alkene and not alkadiene. So, these are the only types of alkenes that can be formed which are structural isomers.

    [JEE Main 2013 Online Exam]
    • a)
      a
    • b)
      b
    • c)
      c
    • d)
      d
    Correct answer is option 'C'. Can you explain this answer?

    Om Desai answered
     In ethers, alcohols and amines, there is no double bond. However, esters have one double bond as same as monocarboxylic acid. So monocarboxylic  acid is a functional isomer of ester (only for no. of carbon greater than 2. As we need to have at least 3 carbon atoms to form ester.)

    • a)
      a
    • b)
      b
    • c)
      c
    • d)
      d
    Correct answer is option 'B'. Can you explain this answer?

    Om Desai answered
    Double bond equivalent of C5H10O is 1. So, it will have either a double bond or a ring.So, it may be an aldehyde, ketone, alcohol( carbon chain having double bond) or epoxide.
    Propyl ethanoate has 2 oxygen atoms. So, it will never be its isomer. HOwever option a and c will be its isomer as they are aldehyde.

    Match the systems in Column I with their corresponding characterstics from Column II
    Codes 
        
    • a)
      a
    • b)
      b
    • c)
      c
    • d)
      d
    Correct answer is option 'A'. Can you explain this answer?

    Lavanya Menon answered
    The correct answer is option A
    i. Butanone- q) Has three tautomers other than the mentioned compound.
    s) Acts as H-bonds acceptor.
    ii. 3-pentanone- p) has two tautomer’s other than the mentioned compound itself
    s) Acts as H-bonds acceptor.
    iii. Methanamide - p) has two tautomer’s other than the mentioned compound itself
    r) Form intermolecular H-bonds with its own molecules.
    s) Acts as H-bonds acceptor.
    Iv. Ethane nitrite - p) has two tautomer’s other than the mentioned compound itself
    s) Acts as H-bonds acceptor.
     

    Which of the following correctly ranks the cycloalkanes in order of increasing ring strain per methylene group? 
    • a)
      Cyclopropane < Cyclobutane < Cyclopentane < Cyclohexane 
    • b)
      Cyclohexane < Cyclopentane < Cyclobutane < Cyclopropane 
    • c)
      Cyclohexane < Cyclobutane < Cyclopentane < Cyclopropane 
    • d)
      Cyclopropane < Cyclopentane < Cyclobutane < Cyclohexane  
    Correct answer is option 'B'. Can you explain this answer?

    Rajesh Gupta answered
    The correct answer is Option B.

    The C-C-C bond angles in cyclopropane (60o) and cyclobutane (90o) are much different than the ideal bond angle of 109.5o.This bond angle causes cyclopropane and cyclobutane to have a high ring strain. However, molecules, such as cyclohexane and cyclopentane, would have a much lower ring strain because the bond angle between the carbons is much closer to 109.5o.

    The organic reaction which proceeds through heterolytic bond cleavage are known as:
    • a)
      Covalent reactions
    • b)
      Ionic reactions
    • c)
      Free radical reaction
    • d)
      Polar reactions
    Correct answer is option 'B'. Can you explain this answer?

    Hansa Sharma answered
    In heterolytic bond cleavage the bond breaks unevenly and the shared pair of electrons is accommodated by one of the products, which produces one or more ions.As heterolytic bond cleavage gives ions. So the reaction which proceeds through heterolytic bond cleavage is an ionic reaction.
    Hence B is the correct answer.

    A species having a carbon atom possessing a sextet of electrons and a positive charge is called as:
    • a)
      Chirality
    • b)
      Metamerism
    • c)
      Carbocation
    • d)
      Carbaanion
    Correct answer is option 'C'. Can you explain this answer?

    Rounak Desai answered
    Carbocation:

    A carbocation is a species that contains a positively charged carbon atom. It is formed when a carbon atom loses a pair of electrons, leaving it with only six electrons in its valence shell. This electron deficiency makes the carbon atom highly reactive and prone to attracting electrons from nearby atoms or molecules.

    Structure and Bonding:

    In a carbocation, the carbon atom is attached to three other atoms or groups. It forms three sigma bonds by overlapping its atomic orbitals with the orbitals of the other atoms or groups. These sigma bonds provide stability to the positively charged carbon atom.

    The carbon atom in a carbocation possesses only six electrons in its valence shell, which results in an incomplete octet. It is called a sextet because it has six valence electrons instead of the usual eight. The positive charge on the carbon atom indicates that it has lost an electron, resulting in a deficiency of negative charge.

    Reactivity:

    Carbocations are highly reactive species due to their electron deficiency. They are electron acceptors and can react with nucleophiles, which are electron-rich species. The nucleophile donates a pair of electrons to the positively charged carbon atom, neutralizing the charge and forming a new bond.

    The reactivity of a carbocation depends on its stability. Carbocations can be classified into three types based on the number of alkyl groups attached to the positively charged carbon atom:

    1. Primary carbocation: It has one alkyl group attached to the carbon atom.
    2. Secondary carbocation: It has two alkyl groups attached to the carbon atom.
    3. Tertiary carbocation: It has three alkyl groups attached to the carbon atom.

    Tertiary carbocations are more stable than secondary carbocations, and secondary carbocations are more stable than primary carbocations. This stability is due to the electron-donating nature of the alkyl groups, which helps to disperse the positive charge on the carbon atom.

    Applications:

    Carbocations are intermediates in many organic reactions, including electrophilic additions, rearrangements, and substitution reactions. Understanding their reactivity and stability is crucial in organic chemistry for predicting reaction mechanisms and designing synthetic routes.

    A sequential account of each step, describing details of electron movement, energetics during bond cleavage and bond formation, and the rates of transformation of reactants into products (kinetics) is referred to as:
    • a)
      Reaction mechanism
    • b)
      Reaction kinetics
    • c)
      Thermodynamics
    • d)
      Equation
    Correct answer is option 'A'. Can you explain this answer?

    Rounak Desai answered
    Reaction Mechanism

    The correct answer is option 'A', reaction mechanism. A reaction mechanism provides a detailed account of each step involved in a chemical reaction, including the movement of electrons, the energetics during bond cleavage and bond formation, and the rates of transformation of reactants into products. It explains how reactant molecules rearrange and bond with each other to form products.

    Electron Movement

    In a chemical reaction, electrons play a crucial role in the formation and breaking of chemical bonds. The movement of electrons determines the reactivity and stability of molecules. The reaction mechanism describes how electrons are transferred or shared between atoms during a reaction. It explains the movement of electrons from high energy orbitals to low energy orbitals, leading to the formation of new bonds and the breaking of existing bonds.

    Energetics during Bond Cleavage and Bond Formation

    During a chemical reaction, bonds between atoms are broken and new bonds are formed. The reaction mechanism explains the energy changes associated with these processes. Bond cleavage requires an input of energy, known as bond dissociation energy, as bonds are broken. This energy is absorbed from the surroundings. On the other hand, bond formation releases energy, known as bond formation energy, as new bonds are created. The reaction mechanism describes the energy changes during these processes and how they influence the overall energetics of the reaction.

    Rates of Transformation (Kinetics)

    The reaction mechanism also provides information about the rates of transformation of reactants into products. It describes the individual steps involved in the reaction and the order in which they occur. Each step in the mechanism has a specific rate constant associated with it, which determines how fast that step proceeds. The overall rate of the reaction is determined by the slowest step, known as the rate-determining step. The reaction mechanism helps to identify this step and understand the factors that control the reaction rate.

    Conclusion

    In summary, a reaction mechanism is a detailed account of the steps involved in a chemical reaction. It describes the movement of electrons, the energetics during bond cleavage and bond formation, and the rates of transformation of reactants into products. Understanding the reaction mechanism is crucial for predicting and controlling chemical reactions.

     Which among the following does not exhibit geometric isomerism
    • a)
      1-hexene
    • b)
      2-hexene
    • c)
      3-hexene
    • d)
      4-hexene
    Correct answer is option 'A'. Can you explain this answer?

    Alkenes like 1-hexene when flipped from top to bottom they have identical structures and also they have C=CH2 unit which does not exist as cis- trans isomers.

     Which among the following is a very unstable and reactive species:
    • a)
      Carbaanion
    • b)
      Polar ions
    • c)
      Carbocation
    • d)
      Free radical
    Correct answer is option 'C'. Can you explain this answer?

    Geethika Reddy answered
    Actually carbanions are filled with octet, so they are stable and less reactive, in case of polar ions already they are stable, and free radicle is heptet i.e, near to octet whereas carbocation is sextet in nature, so in order to gain to octet it is more reactive and less stable

    How many cyclic Isomers (structural and geometrical only) exist for C5H10
    • a)
      8
    • b)
      6
    • c)
      5
    • d)
      3
    Correct answer is option 'C'. Can you explain this answer?

    Lavanya Menon answered
    5 isomers are possible. C5H10(CnH2n). Molecules having the CnH2n  formula are most likely to be cyclic alkanes. The five isomers are:

    The correct statement(s) about the compound given below is/are
    • a)
      The compound is optically active
    • b)
      The compound possesses centre of symmentry
    • c)
      The Compound possesses plane of symmetry
    • d)
      the compound possessses axis of symmetry
    Correct answer is option 'A,D'. Can you explain this answer?

    Pooja Shah answered
    The correct answer is option A & D
    The given image is Self-Explanatory.
    We know that following are the cases when a compound is Optically Inactive:
    1. When it does not have a chiral Carbon Atom eg.: Methyl bromide
    2. When it has a Plane or Axis of Symmetry eg.: Tartaric Acid (these compounds are called as Meso Compounds)
    3. When it forms a Racemic Mixture eg.: Equimolar mixture of d-Lactic Acid and l-Lactic Acid.
    The given compound in the question possesses an Axis of Symmetry (shown in the attached image). Hence, it is Optically Inactive.
     

    • a)
      a
    • b)
      b
    • c)
      c
    • d)
      d
    Correct answer is option 'B'. Can you explain this answer?

    Preeti Iyer answered
    The correct answer is Option B.
     
     
    CH3−CH=CH−CH=CH−CH3
              2,4-hexadiene
     
    Three different geometrical isomers of cis-cis, trans-trans and sic-trans are possible.
     

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