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    Konsep Mol

    Uploaded by

    Viand Nugroho
    The document discusses concepts related to molar mass, molecular mass, formula mass, and moles. It provides examples of calculating molar mass from atomic mass values, determining the number of atoms or moles in a given mass of a substance, and calculating molecular and formula masses from summing atomic masses in chemical formulas. Key formulas introduced include relating grams of a substance to moles using molar mass, and that 1 mole contains 6.022 x 1023 elementary entities like atoms or molecules.

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    Konsep Mol

    Uploaded by

    Viand Nugroho
    14 views15 pages
    The document discusses concepts related to molar mass, molecular mass, formula mass, and moles. It provides examples of calculating molar mass from atomic mass values, determining the number of atoms or moles in a given mass of a substance, and calculating molecular and formula masses from summing atomic masses in chemical formulas. Key formulas introduced include relating grams of a substance to moles using molar mass, and that 1 mole contains 6.022 x 1023 elementary entities like atoms or molecules.

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    KONSEP MOL

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    The document discusses concepts related to molar mass, molecular mass, formula mass, and moles. It provides examples of calculating molar mass from atomic mass values, determining the number of atoms or moles in a given mass of a substance, and calculating molecular and formula masses from summing atomic masses in chemical formulas. Key formulas introduced include relating grams of a substance to moles using molar mass, and that 1 mole contains 6.022 x 1023 elementary entities like atoms or molecules.

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    14 views15 pages

    Konsep Mol

    Uploaded by

    Viand Nugroho
    The document discusses concepts related to molar mass, molecular mass, formula mass, and moles. It provides examples of calculating molar mass from atomic mass values, determining the number of atoms or moles in a given mass of a substance, and calculating molecular and formula masses from summing atomic masses in chemical formulas. Key formulas introduced include relating grams of a substance to moles using molar mass, and that 1 mole contains 6.022 x 1023 elementary entities like atoms or molecules.

    Copyright:

    © All Rights Reserved
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    Download as pptx, pdf, or txt
    of 15

    KONSEP MOL

    RENY ROSALINA, M.SI


    Micro World Macro World
    atoms & molecules grams

    Atomic mass is the mass of an atom in atomic


    mass units (amu)
    By definition:
    1 atom 12C “weighs” 12 amu

    On this scale
    1
    H = 1.008 amu
    16
    O = 16.00 amu
    3.1
    Natural lithium is:
    7.42% 6Li (6.015 amu)
    92.58% 7Li (7.016 amu)

    Average atomic mass of lithium:

    7.42 x 6.015 + 92.58 x 7.016


    = 6.941 amu
    100

    3.1
    Average atomic mass (6.941)
    The mole (mol) is the amount of a substance that
    contains as many elementary entities

    1 mol = 12.00 g of 12C


    1 mol = NA = 6.0221367 x 1023
    Avogadro’s number (NA)
    Molar mass is the mass of 1 mole of atoms in grams

    1 mole 12C atoms = 6.022 x 1023 atoms = 12.00 g


    1 12C atom = 12.00 amu

    1 mole 12C atoms = 12.00 g 12C


    1 mole lithium atoms = 6.941 g of Li

    For any element


    atomic mass (amu) = molar mass (grams)
    mass (gr) mass
    ( gr )
    mol = ----------------- or mol =
    ----------------
    Ar Mr

    M = molar mass in g/mol


    NA = Avogadro’s number
    3.2
    Do You Understand Molar Mass?
    How many atoms are in 0.551 g of potassium (K) ?

    1 mol K = 39.10 g K
    1 mol K = 6.022 x 1023 atoms K

    1 mol K 6.022 x 1023 atoms K


    0.551 g K x x =
    39.10 g K 1 mol K

    8.49 x 1021 atoms K


    Zinc (Zn) is a silvery metal that is used in making brass (with copper) and in plating iron to prevent
    corrosion. How many moles of Zn are there in 45.9 g of Zn?atomic mass of Zn 65.39 amu

    1 mol K
    45.9 g Zn x = 0.702 mol
    65.39 g K
    Molecular mass (or molecular weight) is the sum of
    the atomic masses (in amu) in a molecule.

    1S 32.07 amu
    2O + 2 x 16.00 amu
    SO2 SO2 64.07 amu

    For any molecule


    molecular mass (amu) = molar mass (grams)

    1 molecule SO2 = 64.07 amu


    1 mole SO2 = 64.07 g SO2
    Calculate the molecular masses (in amu) of the following compounds: (a) Urea
    ((NH2)2CO) and (b) caffeine (C8H10N4O2).

    molecular mass of (NH2)2CO = 2(14.01 amu) + 4(1.008 amu) + 12.01 amu + 16.00 amu
    = 60.06 amu

    molecular mass of C8H10N4O2 = 8(12.01 amu) + 10(1.008 amu) + 4(14.01 amu) + 2(16.00 amu)
    = 194.20 amu

    How many moles in 43.8 g of urea [(NH2)2CO], which is used as a fertilizer, in animal feed, and in the
    manufacture of polymers?

    1 mol urea
    43.8 g Urea x = 0.729 mol
    60.06 g K
    Do You Understand Molecular Mass?
    How many H atoms are in 72.5 g of C3H8O ?

    1 mol C3H8O = (3 x 12) + (8 x 1) + 16 = 60 g C3H8O


    1 mol C3H8O molecules = 8 mol H atoms
    1 mol H = 6.022 x 1023 atoms H

    1 mol C3H8O 8 mol H atoms 6.022 x 1023 H atoms


    72.5 g C3H8O x x x =
    60 g C3H8O 1 mol C3H8O 1 mol H atoms

    5.82 x 1024 atoms H


    Formula mass is the sum of the atomic masses
    (in amu) in a formula unit of an ionic compound.

    1Na 22.99 amu


    NaCl 1Cl + 35.45 amu
    NaCl 58.44 amu

    For any ionic compound


    formula mass (amu) = molar mass (grams)

    1 formula unit NaCl = 58.44 amu


    1 mole NaCl = 58.44 g NaCl
    Do You Understand Formula Mass?
    What is the formula mass of Ca3(PO4)2 ?

    1 formula unit of Ca3(PO4)2


    3 Ca 3 x 40.08
    2P 2 x 30.97
    8O + 8 x 16.00
    310.18 amu

    3.3

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