Question

Which of the following is the wrong statement? (a) Ozone is violet black in solid state (b) Ozone is diamagnetic gas (c) ONCl and \(\mathrm{ONO}^{-}\)are isoelectronic (d) \(\mathrm{O}_{3}\) molecule is bent

Short answer

Statement (c) is incorrect: ONCl and ONO- are not isoelectronic.

Step-by-step solution

Understand the properties of ozone (O3)

Ozone (O3) is a triatomic molecule consisting of three oxygen atoms. In its solid state, ozone appears violet-black. Additionally, ozone is known to be a diamagnetic gas because all of its electrons are paired, making statements (a) and (b) correct.

Analyze the molecular structure of O3

The \(\mathrm{O}_3\) molecule, or ozone, has a bent molecular shape because the central oxygen forms two double bonds with the surrounding oxygen atoms, leading to a non-linear structure. This makes statement (d) correct.

Examine the isoelectronic properties of ONCl and ONO-

Isoelectronic species have the same number of electrons. \(\mathrm{ONCl}\) (Oxygen, Nitrogen, Chlorine) and \(\mathrm{ONO}^{-}\) (Oxygen, Nitrogen, Oxygen ion with an extra electron) are not isoelectronic. While ONCl has 24 electrons, ONO- has 23 electrons (since nitrogen typically has 5, oxygen has 6 each, chloride doesn’t change total count, but the minus in \(\mathrm{ONO}^{-}\) adds one to oxygen’s 6), making statement (c) incorrect.

Key concepts

Ozone Properties

Ozone ( O_3 ) is a fascinating molecule composed of three oxygen atoms bonded together. When in a solid state, ozone exhibits a striking violet-black color. This unique hue is due to its molecular structure and how it interacts with light. A lesser-known property of ozone is its behavior in its gaseous state, where it acts as a diamagnetic substance. Diamagnetism occurs because all electrons in ozone are paired, leaving no unpaired electrons that would contribute to magnetic attraction. This means that ozone is slightly repelled by a magnetic field. It's important to recognize these properties as they help in identifying ozone and understanding its role in atmospheric and chemical processes.

Diamagnetism

Diamagnetism is a property of substances where there is a zero net magnetic moment. This characteristic arises from all electrons being paired, which is the case for ozone ( O_3 ). In diamagnetic substances, when placed in a magnetic field, the magnetic forces slightly repel these molecules. This effect is generally weak compared to other types of magnetism, such as ferromagnetism or paramagnetism. An everyday example of diamagnetism can be seen when using common materials like water or graphite, which similarly exhibit this repulsion to magnetic fields. Understanding diamagnetism in ozone can help you grasp its chemical behavior in different environmental conditions. It's intriguing to note how something as common as a triatomic oxygen molecule can possess such distinctive magnetic properties.

Bent Molecular Shape

A bent molecular shape occurs when molecules have a central atom bonded to others but are not arranged in a straight line. Ozone ( O_3 ) is a quintessential example of this configuration. This shape results from the central oxygen atom forming bonds with two other oxygen atoms, but due to repulsion forces and the presence of lone electron pairs, the molecule bends. This molecular structure affects properties like polarity and reactivity.
- The angle in the ozone molecule is approximately 116.8 degrees, compared to the linear structure's 180 degrees. - Such angular arrangements in molecules often lead to unique chemical reactions and optical characteristics.
Understanding the bent shape of ozone can illuminate why it's so reactive and participates actively in many atmospheric reactions.

Isoelectronic Species

Isoelectronic species are entities that share the same number of electrons, thus often having similar chemical properties. However, this does not mean they are identical or have the same reactivity or geometry.
- In the given problem, ONCl (oxygen, nitrogen, chlorine) and ONO^- (an ion with three oxygen atoms) are examined for isoelectronicity. - The total electron count for ONCl is 24, with contributions from each atom fitting conventional electron counts. - ONO^- has one fewer electron in comparison, with a total of 23 electrons because of the extra negative charge.
Therefore, they are not isoelectronic. Recognizing whether two species are isoelectronic helps predict chemical behavior and potential reactivity in compounds.