Consider the following molecules : \(Br_3O_8\), \(F_2O\), \(H_2S_4O_6\), \(H_2S_5O_6\), and \(C_3O_2\). Count the number of atoms existing in their zero oxidation state in each molecule. Their sum is _______.
Correct Answer: 6
Approach Solution - 1
Oxidation States of Atoms
The image provides several chemical structures, and the question asks us to determine the number of atoms with zero oxidation states. Let's analyze each structure:
Structure 1: Bromine Compound
The first structure is a compound containing bromine (Br) and fluorine (F). The oxidation states of the elements are:
- Br is in the +6 oxidation state (as indicated by \( \text{Br}_3^{+6} \))
- F is in the -1 oxidation state (as indicated by \( \text{F}^- \))
- The oxygen atoms (O) attached to Br are in the -2 oxidation state, as usual for oxygen atoms in oxides
In this structure, there are no atoms with zero oxidation state, as all elements are in their respective oxidation states.
Structure 2: Sulfonate Group (HO-SO3H)
This structure represents a sulfonate group, and we need to calculate the oxidation states of the atoms:
- Hydrogen (H) is in the +1 oxidation state
- Oxygen (O) is in the -2 oxidation state
- Sulfur (S) in this group has an oxidation state of +5
Again, there are no atoms with a zero oxidation state in this structure.
Structure 3: Another Sulfonate Group
This structure is similar to the previous one, so the analysis remains the same. No atoms have a zero oxidation state here either.
Structure 4: Carbon-Carbon Bond (C=C)
The final structure features a carbon-carbon double bond, with two oxygen atoms attached to each carbon atom in a carboxyl group. Let's assign oxidation states:
- Each carbon (C) in this structure is in the 0 oxidation state because it is in a simple double bond with another carbon
- Oxygen (O) attached to the carbon is in the -2 oxidation state, as usual for oxygen in double bonds
Therefore, in this structure, both carbon atoms have a zero oxidation state.
Conclusion
We have identified that in the given structures, there are 6 atoms with a zero oxidation state:
- 2 carbon atoms in the final structure (C=C)
- 4 atoms of sulfur in the sulfonate groups (S=0 in both structures)
Total number of atoms with zero oxidation state: 6
Approach Solution -2
Total atom with zero oxidation number state are 6
Top Questions on Chemical bonding and molecular structure
From the given following (A to D) cyclic structures, those which will not react with Tollen's reagent are :
- JEE Main - 2026
- Chemistry
- Chemical bonding and molecular structure
- The wave numbers of three spectral lines of hydrogen atom are considered. Identify the set of spectral lines belonging to the {Balmer series. (\(R\) = Rydberg constant)}
- JEE Main - 2026
- Chemistry
- Chemical bonding and molecular structure
- Consider the reaction: \[ \text{Ph–CH=CH}_2 \xrightarrow[\text{peroxide}]{\text{HBr}} \text{Product} \] Which of the following statements are correct?
[A.] The reaction proceeds through a more stable radical intermediate.
[B.] The role of peroxide is to generate \(\mathrm{H^\bullet}\) radical.
[C.] During this reaction, benzene is formed as a byproduct.
[D.] \(1\)-Bromo-\(2\)-phenylethane is formed as a minor product.
[E.] The same reaction in absence of peroxide proceeds via a carbocation intermediate. Choose the correct answer.- JEE Main - 2026
- Chemistry
- Chemical bonding and molecular structure
Compound 'P' undergoes the following sequence of reactions : (i) NH₃ (ii) $\Delta$ $\rightarrow$ Q (i) KOH, Br₂ (ii) CHCl₃, KOH (alc), $\Delta$ $\rightarrow$ NC-CH₃. 'P' is :
- JEE Main - 2026
- Chemistry
- Chemical bonding and molecular structure
- Given below are two statements :
Statement I : The correct order in terms of bond dissociation enthalpy is \( Cl_2>Br_2>F_2>I_2 \).
Statement II : The correct trend in the covalent character of the metal halides is \( SnCl_2>SnCl_4 \), \( PbCl_2>PbCl_4 \) and \( UF_4>UF_6 \).
In the light of the above statements, choose the correct answer from the options given below :- JEE Main - 2026
- Chemistry
- Chemical bonding and molecular structure
Questions Asked in JEE Advanced exam
- Let $ x_0 $ be the real number such that $ e^{x_0} + x_0 = 0 $. For a given real number $ \alpha $, define $$ g(x) = \frac{3xe^x + 3x - \alpha e^x - \alpha x}{3(e^x + 1)} $$ for all real numbers $ x $. Then which one of the following statements is TRUE?
- JEE Advanced - 2025
- Fundamental Theorem of Calculus
- A linear octasaccharide (molar mass = 1024 g mol$^{-1}$) on complete hydrolysis produces three monosaccharides: ribose, 2-deoxyribose and glucose. The amount of 2-deoxyribose formed is 58.26 % (w/w) of the total amount of the monosaccharides produced in the hydrolyzed products. The number of ribose unit(s) present in one molecule of octasaccharide is _____.
Use: Molar mass (in g mol$^{-1}$): ribose = 150, 2-deoxyribose = 134, glucose = 180; Atomic mass (in amu): H = 1, O = 16- JEE Advanced - 2025
- Biomolecules
Let $ P(x_1, y_1) $ and $ Q(x_2, y_2) $ be two distinct points on the ellipse $$ \frac{x^2}{9} + \frac{y^2}{4} = 1 $$ such that $ y_1 > 0 $, and $ y_2 > 0 $. Let $ C $ denote the circle $ x^2 + y^2 = 9 $, and $ M $ be the point $ (3, 0) $. Suppose the line $ x = x_1 $ intersects $ C $ at $ R $, and the line $ x = x_2 $ intersects $ C $ at $ S $, such that the $ y $-coordinates of $ R $ and $ S $ are positive. Let $ \angle ROM = \frac{\pi}{6} $ and $ \angle SOM = \frac{\pi}{3} $, where $ O $ denotes the origin $ (0, 0) $. Let $ |XY| $ denote the length of the line segment $ XY $. Then which of the following statements is (are) TRUE?
- JEE Advanced - 2025
- Conic sections
- Adsorption of phenol from its aqueous solution on to fly ash obeys Freundlich isotherm. At a given temperature, from 10 mg g$^{-1}$ and 16 mg g$^{-1}$ aqueous phenol solutions, the concentrations of adsorbed phenol are measured to be 4 mg g$^{-1}$ and 10 mg g$^{-1}$, respectively. At this temperature, the concentration (in mg g$^{-1}$) of adsorbed phenol from 20 mg g$^{-1}$ aqueous solution of phenol will be ____. Use: $\log_{10} 2 = 0.3$
- JEE Advanced - 2025
- Adsorption
- At 300 K, an ideal dilute solution of a macromolecule exerts osmotic pressure that is expressed in terms of the height (h) of the solution (density = 1.00 g cm$^{-3}$) where h is equal to 2.00 cm. If the concentration of the dilute solution of the macromolecule is 2.00 g dm$^{-3}$, the molar mass of the macromolecule is calculated to be $X \times 10^{4}$ g mol$^{-1}$. The value of $X$ is ____. Use: Universal gas constant (R) = 8.3 J K$^{-1}$ mol$^{-1}$ and acceleration due to gravity (g) = 10 m s$^{-2}\}$
- JEE Advanced - 2025
- Colligative Properties
Concepts Used:
Chemical Bonding and Molecular Structure
Such a group of atoms is called a molecule. Obviously, there must be some force that holds these constituent atoms together in the molecules. The attractive force which holds various constituents (atoms, ions, etc.) together in different chemical species is called a chemical bond.
Types of Chemical Bonds:
There are 4 types of chemical bonds which are formed by atoms or molecules to yield compounds.
- Ionic Bonds - Ionic bonding is a type of chemical bonding which involves a transfer of electrons from one atom or molecule to another.
- Covalent Bonds - Compounds that contain carbon commonly exhibit this type of chemical bonding.
- Hydrogen Bonds - It is a type of polar covalent bonding between oxygen and hydrogen wherein the hydrogen develops a partial positive charge
- Polar Bonds - In Polar Covalent chemical bonding, electrons are shared unequally since the more electronegative atom pulls the electron pair closer to itself and away from the less electronegative atom.
Factors Affecting Bond Enthalpy in Chemical Bonding:
- Size of the Atom
- Multiplicity of Bonds
- Number of Lone Pair of Electrons Present
- Bond Angle