Shweta Thakur posted an Question
August 21, 2020 • 21:53 pm 30 points
  • IIT JAM
  • Chemistry (CY)

Why tungsten has highest melting point than cr and mo

why tungsten has highest melting point than cr and mo

2 Answer(s) Answer Now
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  • Amol ashok pawar best-answer

    The low thermal expansion and high melting point and tensile strength of tungsten originate from strong covalent bonds formed between tungsten atoms by the 5d electrons. More the electrons higher the melting point.

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    Dinesh khalmaniya 1 Best Answer

    The maxima at about the middle of each indicate that one unpaired electron per d orbital is particularly favourable of strong interatomic intersection. In general , greater he number of valence electrons, Stronger is the resultant bonding. Cr,Mo and W have maximum number of unpaired electrons and therefore , these are very hard metals and have maximum enthalpies of atomization. So tungsten has very melting point.

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    check this video https://doubtnut.com/question-answer-chemistry/statement-1-tungsten-has-very-high-melting-point-statament-2-tungsten-is-a-convalent-compounds-14160735

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    sir cr and Mo have also 6 Valence electrons

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    and w also has 6

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    did you check this video?

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    yes sir

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    wait...

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    Cr has 5 unpaired electrons n?

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    and for mo?

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    and w?

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    these belongs to same group having d5 electrons, wait I'll explain everything

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    okokok

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    yes sweta now I'm free

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    so what is your doubt?

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    VIB group have more number of inpaired electrons (s1,d5) so these are strong electrostatic force of attraction and have high MP

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    down the group Size increase so molecular weight increase. also VF of attraction increase so Melting point increase hence W have most melting point

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