Tag: chemical bonding and structure

Questions Related to chemical bonding and structure

Identify the alloy containing a non- metal as a constituent in it.

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

  1. Bell metal

  2. Bronze

  3. Invar

  4. Steel

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Correct Option: A

Spiegeleisen is an alloy of :

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

  1. $Cu+Zn+Ni$

  2. $Ni+Cr$

  3. $Mn+si+C$

  4. $Fe+Cr+Ni$

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Correct Option: C
Explanation:

Spiegeleisen is a ferromanganese alloy.
It contains iron, manganese and carbon.
Manganese is present to about 15%.

An alloy of copper, silver and gold is found to have copper constituting the ccp lattice. If silver atoms occupy the edge wares and gold is resent at a body centre. the alloy has a formula?

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

  1. $ Cu _{4}Ag _{2}Au $

  2. $ Cu _{4}Ag _{4}Au $

  3. $ Cu _{4}Ag _{3}Au $

  4. CuAgAu

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Correct Option: C

Bell metal is an alloy of :

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

  1. Sn+Pb

  2. Cu+Sn

  3. Sn+Sb

  4. none of these

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Correct Option: C

Which of the following is an alloy?

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

  1. Silver

  2. Gallium

  3. $22$ carat gold

  4. $24$ carat gold

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Correct Option: C
Explanation:

22 karat gold contains 22 parts gold and 2 parts of other metals added as alloy. ... 18 karat gold contains 18 parts pure gold with 6 parts of other metals added. In the West the karat is expressed in fineness.

Hence 22 carat gold is an alloy.

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.