Maharashtra Board Class 12 Solutions for Chemistry Chapter 16 Green Chemistry and Nano Chemistry - PDF

1. Choose The Most Correct Option.

1. The development that meets the needs of the present without compromising the ability of future generations to meet their own need is known as

1. Continuous development

2. Sustainable development

3. True development

4. Irrational development

Ans: The correct option is b) Sustainable development.

Sustainable development is defined as growth that satisfies existing demands without compromising the capacity of future generations to meet their own needs.

2. Which of the following is ϒ-isomer of BHC?

1. DDT

2. Lindane

3. Chloroform

4. Chlorobenzene

Ans: The correct option is b) Lindane.

BHC, often known as benzene hexachloride, is a common insecticide today. The gamma-isomer of BHC is known as gammexane or lindane.

3. The prefix ‘nano’ comes from

1. French word meaning billion

2. Greek word meaning dwarf

3. Spanish word meaning particle

4. Latin word meaning invisible

Ans: The correct option is b) Greek word meaning dwarf.

The Greek word "nano" means "dwarf," but in this context, it refers to anything that is much tiny than a dwarf. One to one hundred nm is referred to as the nanometer scale. One nanometer equals one billionth of a metre.

4. Which of the following information is given by FTIR technique?

1. Absorption of functional groups

2. Particle size

3. Confirmation of formation of nanoparticles

4. Crystal structure

Ans: The correct option is a) Absorption of functional groups.

In order to learn more about the nature of binding and the absorption of functional groups, FTIR, or Fourier transforms infrared spectroscopy, is used.

5. The concept of green chemistry was coined by

1. Born Haber

2. Nario Taniguchi

3. Richard Feynman

4. Paul T. Anastas

Ans: The correct option is d) Paul T. Anastas.

An approach to chemistry known as "green chemistry" seeks to enhance effectiveness while minimising any harmful impacts on both human health and the environment. Paul T. Anastas is the author of the phrase "green chemistry."

2. Answer The Following.

1. Write the formula to calculate % atom economy.

Ans: The following equation can be used to calculate the % atom economy:

$% \ Atom \ Economy = \dfrac{Formula \ weight \ of \ the \ desired \ product}{Sum \ of \ formula \ weight \ of \ all \ reactants \ used} \times 100$

2. Name the ϒ-isomer of BHC.

Ans: The substance, which is an isomer of hexachlorocyclohexane, is employed both as an insecticide and a medication for treating lice. To kill hair bugs, it is also included in shampoos. The gamma isomer's name is Lindane, also referred to as gamma-hexachlorocyclohexane.

3. Ridhima wants to detect the structure of the surface of materials. Name the technique she has to use.

Ans: Ridhima seeks to identify the composition of a material's surface. She must therefore employ surface science as a technique. The study of surface detection of materials is known as surface science or structure. It is employed to investigate the physical and chemical properties of a variety of surfaces and interfaces.

4. Which nanomaterial is used for car tires to increase the life of tyres?

Ans: To extend the life and durability of automotive tyres, nano-silica is utilised in them. Large specific surface area, strong surface adsorption, high surface energy, high chemical purity, and good dispersion are the key benefits that make it an obvious choice. The first option for tyres is nano-silica due to its resilience.

5. Name the scientist who discovered scanning tunnelling microscope (STM) in 1980.

Ans: The Scanning Tunnelling Microscope, or STM, was developed by Gerd Binding and Heinrich Rohrer at IBM Zurich as a tool for imaging surfaces at the atomic level.

6. 1 nm = …..m?

Ans: Utilising the method of conversion from metres to nanometers. The following is the response to the query: 

• 1 nm = 109

3. Answer The Following.

1. Define

1. Green chemistry

2. Sustainable development.

Ans: 

1. In order to prevent pollution, green chemistry uses chemical processes and products that minimise or completely do away with the usage or production of hazardous materials.

2. Development that satisfies current needs without compromising the ability of future generations to meet their own needs is referred to as sustainable development.

2. Explain the role of green chemistry.

Ans: Chemical synthesis that is friendly to the environment is known as "green chemistry." Any synthesis, whether carried out in industrial settings or research labs, ought to produce little to no byproducts that damage the atmosphere. Paul T. Anastas' research has led to the formulation of the following fundamental concepts of green chemistry:

• Avoiding waste and byproducts

• Maximum reaction-related component incorporation in the finished product.

• Avoiding or reducing the use of dangerous items.

• Creation of safer chemical formulas.

• Any kind of synthesis should have a minimal energy consumption.

• Choosing the most suitable solvent.

• Choosing the right materials for the beginning.

3. Give the full form (long form) of the names for the following instruments.

1. XRD

2. TEM.

3. STM

4. FTIR

5. SEM

Ans: The following are the names of the instruments in question in their entire form:

1. X-ray diffraction

2. Tunneling Electron Microscope

3. Scanning Tunnelling Microscope

4. Fourier Transform Infrared Spectroscopy

5. Scanning Electron Microscope

4. Define the following terms :

1. Nanoscience

2. Nanotechnology

3. Nanomaterial

4. Nanochemistry

Ans: 

1. Nanoscience is the study of phenomena and material manipulation at the atomic, molecular, and macromolecular scales where properties change noticeably from those at a larger scale.

2. Nanotechnology is the design, characterization, manufacture, and use of structures, devices, and systems by manipulating size and form at the nanoscale scale.

3. The term "nanomaterial" refers to a material with structural elements that have at least one dimension between 1 and 100 nm in the nanometer range. Nanomaterials are smaller than germs and organisms but larger than individual atoms.

4. The fusion of chemistry and nanoscience is referred to as nanochemistry. It deals with creating and synthesising nanoscale materials of various sizes, shapes, structures, and compositions, as well as organising them into useful architectural structures.

5. How nanotechnology plays an important role in water purification techniques?

Ans: Given that 1.1 billion people lack access to better water supplies, water purification is a crucial concern. Water contains bacteria and viruses that are water-borne diseases.

To eliminate E. Coli from water, silver nanoparticles are a highly effective bacterial disinfectant. So, to purify water, filter materials covered in silver nanoparticles are used. 

A technology alternative that is reasonably priced is silver nanoparticles. a water filter, as an example.

6. Which nanomaterial is used in sunscreen lotion? Write its use.

Ans: Sunscreen creams contain nanoparticles of zinc oxide (ZnO) and titanium dioxide (TiO2). By absorbing or reflecting light, the chemicals shield the skin from damaging ultraviolet rays and prevent skin damage.

7. How will you illustrate the use of safer solvent and auxiliaries?

Ans: The green chemistry principle of using safer solvents and auxiliaries argues that for chemical synthesis and other uses, safer solvents like water and supercritical CO2 should be used instead of volatile halogenated organic solvents like CH2CI2, CHCI3, and CCI4.

Solvents help numerous reactions happen by dissolving solutes and creating solutions. Water is a more benign and safe solvent than chloroform (CHCI3) and dichloromethane (CH2CI2). 

Every year, the use of harmful solvents has an impact on millions of workers as well as consumers and the environment. Their use generates a lot of trash and has negative effects on both the environment and human health.

The greatest way to enhance the process and the result is to find safer solvents or to build solvent-free processes.

8. Define catalyst. Give two examples.

Ans: A catalyst is a substance that increases the rate of a reaction without undergoing any chemical change as a result of the process. It aids in boosting selectivity, minimising waste, and cutting back on reaction times and energy requirements. For instance: Platinum, palladium, and Raney nickel are catalysts used in the hydrogenation of oil.

4. Answer the following.

1. Explain any three principles of green chemistry.

Ans: Principles of Green Chemistry:

• Since protecting the environment is of utmost importance, it is necessary to create chemicals that can be readily disposed of and decompose. These substances should not be hazardous, bioaccumulative, or ecologically persistent, and neither should the breakdown products they produce.

• This idea tries to make waste products naturally degradable so that the environment can be cleaned. Hence the choice of herbicides and biodegradable polymers.

• An international plastic recycling symbol is put on larger objects to facilitate consumer sorting and segregation.

• It is imperative to create improvised analytical techniques that will enable real-time process monitoring and control before dangerous compounds arise.

• The development or modification of analytical techniques is crucial for the chemical industry and nuclear reactors in order to enable continuous monitoring of the production and processing facilities.

• Chemical processes must be improved to make them safer and reduce the possibility of mishaps. In order to reduce the likelihood of chemical mishaps, explosions, fires, and emissions, it is crucial to carefully choose the chemical ingredients that are employed in chemical reactions.

• For instance, compared to a system that uses nonvolatile liquid and solid components, a chemical process that works with gaseous chemicals can result in considerably higher chances of accidents, including explosions.

2. Explain the atom economy with suitable examples.

Ans: Atom Economy:

• Atom economy measures how effectively all the atoms used in a chemical reaction are converted into the desired products.

• Chemical yield is not as important as the atom economy because high-yielding processes might nevertheless produce significant byproducts.

• In the event that a pendant group is recovered, the atom economy can also be changed.

• Poor atom economy is prevalent in fine chemical or pharmaceutical synthesis, particularly in research, where the desire to quickly and reliably generate a variety of complicated chemicals leads to the employment of diverse and reliable but inefficiently atom-efficient processes.

• Atom economy measures how effectively all the atoms used in a chemical reaction are converted into the desired products. The number of atoms from the starting components that are still in the usable products after the chemical reaction is complete is used to measure it. For instance, the idea of the atom economy describes the quantity of wasteful raw materials or products.

• The following equation can be used to calculate the % atom economy:

$% \ Atom \ Economy = \dfrac{Formula \ weight \ of \ the \ desired \ product}{Sum \ of \ formula \ weight \ of \ all \ reactants \ used} \times 100$

3. How will you illustrate the principle, minimization of steps?

Ans: The idea behind minimization is to keep things as straightforward and compact as feasible. Minimization enhances security by reducing the number of points or things that can go wrong, the number of points open to attack, the length of high-risk exposure, the value of the assets you have to protect, and the repercussions of failure rather than building more walls, implementing more checks, and employing more guards.

Every bit of complexity you add and every bit of information you keep has a cost, and those costs must be compared to the benefit the increase brings.

The illustration of minimising steps is as follows:

• In synthesised organic compounds, a necessary functional group must be added for protection.

• Once more, the functional group's deprotection is necessary at the very end.

• An illustration would be the creation of m-hydroxybenzoic acid from hydroxybenzaldehyde.

4. What do you mean by sol and gel? Describe the sol-gel method of preparation for nanoparticles.

Ans: A sol is a name for a colloidal solution in its liquid condition. There is no clear organisation to the sol. A gel is a colloidal solution's solid or semi-solid phase. The gel has a structure resembling a honeycomb.

• The sol-gel method of making nanoparticles is a wet chemical process that creates an interconnected network using either colloidal particles or a chemical solution.

• Typical precursors include metal chlorides and metal alkoxides. To create a colloid, a system of nanoparticles distributed in a solvent, they go through hydrolysis and the polycondensation reaction. The sol then develops in the direction of creating an inorganic continuous network with a liquid phase.

• In order to create metal-oxo or metal-hydroxo polymers in solution, metal centres must be linked together with oxo or hydroxo bridges.

• The liquid phase is removed from the gel after drying, and subsequent thermal processing (calcination) may be used to further favour and improve mechanical characteristics.

5. Which flower is an example of self-cleaning?

Ans: A self-cleaning plant is a lotus. Super-hydrophobic nanostructures on the leaves of the lotus plant reject water, which carries dirt as it rolls off. In spite of growing in murky water, the lotus plant (Nelumbonucifera) always has clean-looking leaves.

Importance of Class 12 Chemistry Chapter 16 Green Chemistry and Nanochemistry

Green Chemistry deals with the concepts and fundamental principles of sustainable solutions we design for a better future. In this chapter, students will learn about the prevention of waste, designing new chemical processes to reduce waste, learning how to implement atom economy, designing safe chemical formulations, etc.

Nanochemistry, on the other hand, is related to nanoscience. It deals with the micro-scale of various things produced from the manipulation of molecular and macromolecular levels. Nanotechnology is significantly related to nanochemistry. The design of certain chemical products using this technology provides remarkable modern solutions.

This chapter will explain how these two modern branches of Chemistry enable us to lead a better life. It will explain these domains and use these new concepts to design better products and innovative ideas. Green Chemistry and Nanochemistry Class 12 teaches us about sustainability and how to make it possible.

There will be explanations given with proper examples so that students can imbibe the concepts well. They will also be able to utilize these concepts to answer fundamental questions. To make it easier, they can download and refer to the textbook solutions framed by the experts of Vedantu.

Benefits of Green Chemistry and Nanochemistry Class 12 Solutions

• The exercises of this chapter will have conceptual questions asked to check your preparation level. Once you are done preparing, you can evaluate your skills by answering the textbook exercises. Compare and check your answers with the solutions to find out which sections you need to work on more.

• Use the solutions to learn how the experts have answered such questions accurately. The answers are formulated considering the Maharashtra Board Class 12 standards so that you can correlate and learn how to answer such questions during the board exams.

• Your preparation for this chapter will become much better when you solve the Green Chemistry and Nanochemistry Class 12 important questions given with the solutions. Test your skills and design an exam strategy.

• Clarify doubts on your own using these solutions during your study sessions. There is no need to waste time when you have these files at your fingertips. Complete preparing the syllabus and score well in the exams.

Download Green Chemistry and Nanochemistry Class 12 Solutions PDF

Download the free PDF version of these solutions today! Complete your study material and start preparing this chapter in a better way. Stay ahead of the competition by referring to the answering formats used by Vedantu experts for Green Chemistry and Nanochemistry Class 12 exercises. Find out how to score more and ace the board exams.