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4.7.2: Chemical Quantities (Exercises)

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    These are homework exercises taken from the following;

    Chapter 6 of the Ball et al. "The Basics of GOB Chemistry" Textmap.

    Textmap created for "Chemistry" by OpenStax. 

    Textmap created for Chemistry: A Molecular Approach by Nivaldo Tro. Complementary General Chemistry question banks can be found for other Textmaps and can be accessed here. 

    Some questions have been contributed and modified by Kristina Novek

    Using Moles & Avogadro's Number

    1. How many moles of each element are present in 2.67 mol of each compound?

      1. HCl
      2. H2SO4
      3. Al(NO3)3
      4. Ga2(SO4)3

       

    2. How many moles of each element are present in 0.45 mol of each compound?

    a. HCl

    b. H2SO4

    c. Al2(CO3)3

    d. Ga2(SO4)3

     

    3. Calculate the number of atoms or ions of:

    a. 2.00 mole of Fe

    b. 4.36 mol of Si

    c. 1.20 x 10-2 mol of Li+

    d. 0.875 mol of S2-

     

    4. Calculate the number of molecules or formula units of:

    a. 0.0950 mol of H2O 

    b. 3.20 x 10-3 mol of NaCl

    c. 2.06 mol of CaBr2

    d. 0.14 mol of C6H12O6 (glucose)

     

    5. Calculate the number of moles from each of the following.

    a. 6.95 x 1023 atoms of Cu

    b. 7.12 x 1021 molecules of CO2

    c. 3.33 x 1022 ions of Pb4+ 

    d. 7.00  x 1023 formula units of LiNO3

    e. 5.16 x 1020 molecules of N2

     

    6. A 55-kg woman has 7.5 × 10−3 mol of hemoglobin in her blood. How many hemoglobin molecules is this?


    Molar Mass

    1. Calculate the molar mass of each of the following:

    (a) P4

    (b) H2O

    (c) Ca(NO3)2

    (d) CH3CO2H (acetic acid)

    (e) C12H22O11 (sucrose, cane sugar).

     

    2.Calculate the molar mass of each of the following:

    (a) S8

    (b) C5H12

    (c) Sc2(SO4)3

    (d) CH3COCH3 (acetone)

    (e) C6H12O6 (glucose)

     

    3. If 6.63 × 10−6 mol of a compound has a mass of 2.151 mg, what is the molar mass of the compound?

     

    4. of 8.65 moles of a compound has a mass of 1.47 kilograms, what is the molar mass of the compound?

     

    Mole/Mass Conversions

    1. Determine the mass of each of the following:

    (a) 0.0146 mol KOH

    (b) 10.2 mol ethane, C2H6

    (c) 1.6 × 10−3 mol Na2 SO4

    (d) 6.854 × 103 mol glucose, C6 H12 O6

    (e) 2.86 mol Co(NH3)6Cl3

     

    2. The approximate minimum daily dietary requirement of the amino acid leucine, C6H13NO2, is 1.1 g. What is this requirement in moles?

     

    3. Determine the mass in grams of each of the following:

    (a) 0.600 mol of oxygen atoms

    (b) 0.600 mol of oxygen molecules, O2

    (c) 0.600 mol of ozone molecules, O3

     

    4. Determine the number of moles in each of the following:
     
    (a) 86.5 grams of MgSO4
    (b) 2.30 x 102 grams of CO
    (c) 62.8 grams of KCN
    (d) 0.44 grams of Cl2
     
     
    5. One of the chemicals that gives lavender its' pleasant smell is called linalool (C10H18O). If a sample of lavender contained 9.14 x 10-5 grams of linalool, calculate the number of moles of linalool in the sample.
     

    Mass/Particle Conversions

    1. Convert the following given masses to number of particles:
    (a) 4.2 grams of nickel
    (b) 9.30 x 10-2 grams of Br-
    (c) 0.846 grams of hydrogen gas
    (d) 0.44 grams of H2O2 (hydrogen peroxide)
     
     
    2. Convert the following particles to grams:
     
    (a) 7.90 x 1022  formula units of NaOH
    (b) 2.03 x 1024 molecules of C₁₂H₂₂O₁₁ (lactose)
    (c) 8.85 x 1023 atoms of Fe
    (d) 4.34 x 1021 ions of NO2-

    3. Glycerol (C3H8O3) also know as glycerin,  and is commonly used in soaps, toothpaste, and moisturizers.  How many molecules are in one gram of glycerol?

    4. Ammonia (NH3) is mostly used in agriculture as a fertilizer and can be used as a multipurpose cleanser. What is the mass of 9.85 x 1022 molecules of ammonia?

    5. What is the mass of one tin (Sn) atom in grams?

    Percent Composition

    1. The chemical formula for aspirin is C9H8O4. Calculate the mass percent composition of aspirin.
     
    2. Cannabidiol (C21H26O2) also known as CBD is a chemical found in the cannabis plant.  It has been used to treat epilepsy and anxiety. Calculate the mass percent composition of CBD.
     
     
    3.What is the mass percent of of hydrogen in the common pain reliever acetaminophen (C8H9NO2)?

     

    4.7.2: Chemical Quantities (Exercises) is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.