Tag: applied chemistry

Questions Related to applied chemistry

Which of the following are the nanomaterials with only one dimension between 1 nm and 100 nm?

nanochemistry nanotechnology applied chemistry materials chemistry

  1. Nanolayers

  2. Nanotubes

  3. Nanowires

  4. Nanoparticles

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Correct Option: A
Explanation:

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.

In which of the following type of nano material three dimensions are  outside the nano scale technology deals with using?

nanochemistry nanotechnology applied chemistry materials chemistry

  1. One dimensional nano material

  2. Zero dimensional nano material

  3. Two dimensional nano material

  4. Three dimensional nano material

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Correct Option: D
Explanation:

Three-dimensional nanomaterials (3D) are materials that are not confined to the nanoscale in any dimension. This class can contain bulk powders, dispersions of nanoparticles,bundles of nanowires, and nanotubes as well as multi-nanolayers.
Hence option D is correct.

Which of the following are characteristic properties of nano particles?

nanochemistry nanotechnology applied chemistry materials chemistry

  1. More surface area

  2. Quantum effects

  3. Both a and b

  4. None of the above

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Correct Option: C
Explanation:

Two principal factors cause the properties of nanomaterials to differ significantly from other materials: increased relative surface area, and quantum effects. These factors can change or enhance properties such as
reactivity, strength and electrical characteristics.
Hence option C is correct.

Different dyes are used for dyeing different materials. Which of the following statements is false?

dyes dyes and pigments chemistry in daily life applied chemistry chemistry

  1. Nylon can be dyed with acid dyes

  2. Cotton can be directly dyed with malachite green

  3. Terylene is mainly dyed with disperse dyes

  4. Polyacrylonitrile can be dyed with basic dyes

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Correct Option: B
Explanation:

The color of the wool cloth dyed directly by dipping in hot solution of malachite green dye is fast. The color of cotton cloth dyed directly (without using mordant) by dipping in hot solution malachite green is not fast to washing and is of low intensity.

Statement: Tannic acid is a Mordant.

State whether the given statement is true or false.

dyes dyes and pigments chemistry in daily life applied chemistry chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

 Tannic acid is used to mordant cellulose fibres and fabrics before the alum mordant. Many dyestuffs contain tannin (black oak, pomegranate, cutch, fustic, etc) and do not need an additional tannin mordant. Tannins can be clear or they can add colour to the fibre


Hence, the correct option is $true$

Example of basic dye is:

dyes dyes and pigments chemistry in daily life applied chemistry chemistry

  1. alizarin

  2. indigo

  3. martius yellow

  4. malachite green

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Correct Option: A
Explanation:

Basic dye is a stain that is cationic (+ve charged) and so will react with material that is (-ve) negatively charged. Alizarin prominent red dye is a basic dye. Some other examples of basic dyes are methylene blue, crystal violet, basic fuchsin safranin.

 Which of these statements is true about the colorfastness of dyes?

dyes dyes and pigments chemistry in daily life applied chemistry chemistry

  1. If a dye is fast on one type of fiber it will be fast on all kind of fabrics

  2. If a dye is fast to light, it will also be fast to washing

  3. There are no standardized methods of testing colorfastness for dyes

  4. Wool is the most easily dyed fiber and the resulting color will change the least

Show answer
Correct Option: D
Explanation:

 Colour fastness is a professional word used in theprocess of dyeing for textile materials that characterize a material's color resistance to fading or running. The term is generally used for clothes. In different veryties of cloth, wool is the most easily dyed fiber and the resulting color will change the least. 

Alizarin belongs to the class of:

dyes dyes and pigments chemistry in daily life applied chemistry chemistry

  1. vat dyes

  2. mordant dyes

  3. substantive dyes

  4. reactive dyes

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Correct Option: B
Explanation:
Alizarin belongs to the mordant type of dyes. It is a red dye originally obtained from the root of the common madder plant, Rubia tinctorum, in which it occurs combined with the sugars xylose and glucose.

It is mainly used in biological research. It stains free calcium and certain calcium compounds with a red or light purple color.

Colloidal solutions are classified on the basis of:

dyes dyes and pigments chemistry in daily life applied chemistry chemistry

  1. molecular size

  2. organic or inorganic

  3. surface tension value

  4. pH value

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Correct Option: A

If a solid is dispersed in a liquid, the colloid is known as:

dyes dyes and pigments chemistry in daily life applied chemistry chemistry

  1. gel

  2. sol

  3. emulsion

  4. none of the above

Show answer
Correct Option: B
Explanation:

Sol is a colloidal suspension with solid particles as dispersed phase dissolve in a liquid i.e dispersion medium.

Gel are a dispersion of molecules of a liquid within a solid in which liquid particles are dispersed in the solid medium.
An emulsion is a mixture of two or more liquids that are normally immiscible.
Hence answer is option B