Tag: chemistry

Questions Related to chemistry

Bell-metal is an alloy of

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. Cu+Pb

  2. Cu+Sn

  3. Cu+Zn

  4. Cu+Ni

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Correct Option: B
Explanation:

Bell metal is a hard alloy used for making bells and related instruments, such as cymbals. It is a form of bronze, usually approximately 4:1 ratio of copper to tin (e.g., 78% copper, 22% tin by mass).

Which of the following pairs of elements cannot form an alloy?

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. $Zn,\ Cu$

  2. $Fe,\ Hg$

  3. $Fe,\ C$

  4. $Hg,\ Na$

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Correct Option: B

Which of the following properties of elements can be modified by the formation of alloys?

metals alloys and crystals chemistry elements and compounds alloys and their properties chemical bonding and structure

  1. Resistance to corrosion

  2. Toughness

  3. Malleability & ductility

  4. All of the above

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Correct Option: D
Explanation:

Alloys are used in some applications, where their properties are superior to those of the pure component elements, for a given application. This can include improvement in corrosion resistance (like stainless steel), toughness (like carbon-iron alloys) and malleability-ductility (like wrought iron).

Which of the following methods can be used for the preparation of alloys?

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. Melting a mixture of metals

  2. Simultaneous eletrolytic deposition of metals

  3. By mixing the aqeous solutions of the metal salts

  4. Both 1 and 2

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Correct Option: D
Explanation:

Alloys can either be produced by melting a mixture of metals or simultaneous eletrolytic deposition of metals. This is because alloys are interstitial compounds, and have one atom of a metal inside the solid structure of another atom. This requires mixing in an efficient way, and not just normal physical conditions. 

Raney Nickel is finely divided nickel obtained by digesting alloys of $Ni/Al $ over $NaOH$.

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. True

  2. False

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Correct Option: A
Explanation:
Raney nickel is a fine-grained solid composed mostly of nickel derived from a nickel aluminum alloy
The alloy is treated with a concentrated solution of sodium hydroxide. The simplified leaching reaction is:
$2Al + 2NaOH + 6 H _2O \rightarrow  2 Na[Al{(OH)} _4] + 3 H _2$
After this process, leaching is done to form raney nickel which is powder and spongey.
Given statement is true.

Consider the following statements:
(a) Mass is not affected by temperature and pressure.
(b) Plasma contains ionised gases.
(c) Alloys are homogenous mixtures.
(d) Solution is a heterogeneous mixture.
Which of the above statements are correct?

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. (a), (b) and (c)

  2. (b) and (c)

  3. (a), (c) and (d)

  4. (a) and (d)

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Correct Option: A
Explanation:

a. An increasing or decreasing temperature doesn't affect mass. Mass is the amount of matter in an object whereas temperature is the human sense of kinetic energy of matter. Thermal energy is very, very, very small, so no, it is not measurable as mass.

b. Plasma is the fourth state of matter. Plasma is an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both species, ions and electrons, to coexist.

c. An alloy is a homogeneous mixture of 2 or more metals or metal with 2 or more semi-metals.

d. It is homogeneous because the additions take place in the liquid state, so the atoms mingle with each other and mix thoroughly.

An alloy is a material composed of two or more metals or a metal and a nonmetal. 

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. True

  2. False

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Correct Option: A
Explanation:

An alloy is a material composed of two or more metals or a metal and a nonmetal. An alloy may be a solid solution of the elements (a single phase), a mixture of metallic phases (two or more solutions) or an intermetallic compound with no distinct boundary between the phases. Solid solution alloys give a single solid phase microstructure, while partial solutions exhibit two or more phases that may or may not be homogeneous in distribution, depending on the thermal (heat treatment) history of the material. An inter-metallic compound has one other alloy or pure metal embedded within another pure metal.

The primary metal in an alloy is called:

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. base

  2. metalloid

  3. crystal

  4. none of above

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Correct Option: A
Explanation:

The term alloy is used to describe a mixture of atoms in which the primary constituent is a metal. The primary metal is called the base, the matrix, or the solvent.

Statement 1 : A mixture of pure metals is called an alloy. The melting point of an alloy will be lower than either of the component metal.
Statement 2 : The new bonds are weaker.

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1

  2. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1

  3. Statement 1 is correct but Statement 2 is not correct

  4. Statement 1 is not correct but Statement 2 is  correct

  5. Both the Statement 1 and Statement 2 are not correct

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Correct Option: A
Explanation:

Both Statement 1 and Statement 2 is correct and Statement 2 is the correct explanation of Statement 1.


A mixture of pure metals is called an alloy. The melting point of an alloy will be lower than either of the component metal because the new bonds are weaker.

Hence, the correct option is A.

Tinned iron sheets are used for making boxes for fruits, oils, vegetables etc.

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. True

  2. False

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Correct Option: A
Explanation:

Tinning is the process of thinly coating sheets of wroughtiron or steel with tin, and the resulting product is known as tinplate. While once more widely used, the primary use of tinplate now is the manufacture of tin cans. Formerly, tinplate was used for cheap pots, pans and other holloware. It has an extremely beautiful metallic luster as well as excellent properties in corrosion resistance, solderability, and weldability. 

So it's true.