Tag: applied chemistry

Questions Related to applied chemistry

Which of the following lists the disadvantages of nanomaterials?

  1. Nanomaterials are very expensive.

  2. Nanomaterials are also pretty difficult to manufacture.

  3. Nanoparticles are very small, inhalation of these particles can cause problems.

  4. All of the above.


Correct Option: D
Explanation:

All of the above are the disadvantages of nanomaterials.
Nanomaterials are very expensive.
Also, nanomaterials are also pretty difficult to manufacture
Hence, products made with nanotechnology are more expensive.
Nanoparticles are very small, inhalation of these particles can cause problems similar to the problems from inhaling minute asbestos particles.

Which of the following lists the disadvantages of nanomaterials?

  1. The value of oil may decrease as more efficient sources of energy might be developed which wont require the use of fossil fuels.

  2. Products at the molecular level can be developed, so that diamonds may lose its value due to mass production.

  3. Both of the above

  4. None of the above


Correct Option: C
Explanation:

The following lists the disadvantages of nanomaterials
The value of oil may decrease as more efficient sources of energy might be developed which won't require the use of fossil fuels.
Products at the molecular level can be developed,  so that diamonds may lose its value due to mass production.

The nanomaterials are classified into which of the following?

  1. Nanolayers

  2. Nanotubes or nanowires

  3. Nanoparticles

  4. All of the above


Correct Option: D
Explanation:

The nanomaterials are classified into
nanolayers, nanotubes or nanowires and nanoparticles.
Nanolayers are the nanomaterials with only one dimension between 1 nm and 100 nm.
Nanotubes or nanowires are the nanomaterials with two dimension between 1 nm and 100 nm.
Nanoparticles are the nanomaterials with three dimension between 1 nm and 100 nm.

Gold nanoparticles are highly effective as:

  1. selective oxidation catalysts

  2. selective reduction catalysts

  3. non selective oxidation catalysts

  4. non selective reduction catalysts


Correct Option: A
Explanation:

Gold nanoparticles are highly effective as selective oxidation catalysts. It is used in the oxidation of alcohols and aldehydes.

_______ nanoparticles are widely used in sunscreens and cosmetics, stain resistant fabrics and dirt repellent paints.

  1. The metal oxide

  2. Gold

  3. Silver

  4. The metal sulphide


Correct Option: A
Explanation:

The metal oxide nanoparticles are widely used in sunscreens and cosmetics, stain-resistant fabrics and dirt repellent paints. They are used in sunscreen and cosmetics because they reflect the visible light and absorb UV light efficiently.

Which of the following is true?

  1. The surface of quantum dot can be chemically modified by attaching on organic molecule.

  2. When modified quantum dots bound to a bio-molecule are irradiated with UV light they emit light of a particular wavelength dependent on size of quantum dots.

  3. The modified quantum dots are thousand times smaller than the human cells.

  4. All of the above


Correct Option: D
Explanation:

All of the given statements are true.
The surface of a quantum dot can be chemically modified by attaching an organic molecule. A modified quantum dot targets and forms a chemical bond with a specific biomolecule such as DNA or protein.
The modified quantum dots are thousand times smaller than the human cells. They can easily penetrate cell membranes.
When modified quantum dots bound to a bio-molecule are irradiated with UV light they emit light of a particular wavelength dependent on size of quantum dots. 
If a mixture of quantum dots of different size and different surface modifications are irradiated with a single light source, the detection tracking and having coloured images of a number of different biomolecules within a cell is possible.

In future nanomaterials can be used to detect human cancer at its __________.

  1. earliest and most curable stages

  2. last stage

  3. intermediate stages

  4. all stages


Correct Option: A
Explanation:

In future nanomaterials can be used to detect human cancer at its earliest and most curable stages. Currently, the application of various nanoparticles (including quantum dots) for cancer detection and treatment is under study.

Which of the following are applications of carbon nano tubes?

  1. Catalysis

  2. Biosensor

  3. Drug carriers

  4. All the above


Correct Option: D
Explanation:

As a result of their good physical and chemical properties such as the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively and good electrical and thermal conductor, carbon nano tubes have potential use in a variety of industrial and biomedical applications including: Catalysis, Biosensor, Drug carriers composite materials with improved mechanical and electrical properties. Hence option D is correct

Nano science deals with the scientific study of objects with sizes in the ____ range in at least one dimension.

  1. 200-300 nm

  2. 100-1000 nm

  3. 1-100 nm

  4. 400-500 nm


Correct Option: C
Explanation:

Nanoscience deals with the scientific study of objects with sizes in the 1-100 nm range in one dimension.


In which of the following type of nano material all the dimensions are measured within the nano scale?

  1. Zero dimensional naomaterial

  2. one dimensional naomaterial

  3. Two dimensional naomaterial

  4. Three dimensional naomaterial


Correct Option: A
Explanation:

Accordingly, in zero-dimensional (0D) nanomaterials all the dimensions are measured within the nanoscale (no dimensions are larger than 100 nm). Most commonly, 0D nanomaterials are nanoparticles.
Hence option A is correct.