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Monday January 22, 2024   Day 10
More Moles!   
Textbook Readings:

2.9: Molar Mass Counting Atoms by Weighing

 Course Lectures

3.1  pdf  Video*   Introduction to the mole
Moles to Grams Conversions

Moles to Particles Conversions


Objectives

1. Convert elemental masses into moles and atoms
2. Convert elemental atoms into moles and grams
 


Homework Problems (SHOW ALL WORK FOR CREDIT)

REMEMBER:   You do NOT round numbers obtained from the periodic table before using them.
                             Use molar masses with the greatest accuracy whenever possible.

                             Always round answers appropriately. 
                             However, un-rounded intermediate results should always be used to continue calcs.

10.1  Convert 1.78 grams of mercury metal into moles and atoms of mercury
10.2  Convert 45.0 grams of silicon into moles and atoms of silicon
10.3  Convert 8.1 kg of carbon into moles and atoms of carbon.
10.4  Convert 1.0 ton of copper into moles and atoms of copper
         (1 ton = 2000 pounds exactly ....   1 pound = 453.592 grams)
10.5  Convert 6.022 x 1022 tin atoms into moles and grams of tin
10.6  Convert 4.55 x 108 neon atoms into moles and grams of neon
10.7  Convert 3.5 x 1028 oxygen atoms into moles and kg of oxygen.

Click and Drag below for answers

10.1    8.87 x 10-3 moles  Hg      5.34 x 1021 atoms Hg
10.2    1.60 moles Si                   9.65 x 1023 atoms Si
10.3    670 moles C                    4.1 x 1026  atoms C
10.4    14000 moles Cu               8.6 x 1027 atoms Cu
10.5    0.1000 moles Sn              11.87 g Sn
10.6    7.56 x 10-16 moles Ne      1.52 x 10-14 g Ne
10.7    58000 moles O                930 kg O
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Tuesday January 23, 2024    Day 11
Atoms, Molecules and Chemical Bonds
Textbook Readings:

3.2 Chemical Bonds

 Course Lectures
What's the Difference between an
Atom and a Molecule?
 		Ionic vs. Covalent Bonding


Objectives

1 Describe the ionic bond and its key features
2. Describe the covalent bond and its key features


Homework Problems

11.1  Ionic bonds always involve a metal and a non-metal attracting each other.
         Covalent bonds non-metal ... non-metal combinations.
         Identify each of the following atomic combinations as "Ionic" ,  "Covalent " or "Both"
             a. CO2          b. NaCl       c. PCl4          d. CH3OH       e. MgCO3     
             f. CuCl2         g. SF6         h. PO43-        i.  IO3-              j. Cr(IO3)2

11.2  Where are electrons located when a covalent bond forms?

11.3  Ionic bonds require two charged atoms known as ions.
         How do these two atoms acquire their charge?

11.4  When two oppositely charge ions are released they attract each-other (a.k.a. opposite
          charges attract).  What happens to their energy during this process of crashing towards
          each other? (Think about what the energy of a stretched rubber band does when you
          release it)

11.5   A covalent bond connects two atoms that have the same charge.  These atoms "should"
           repell each-other as "like charges repel).  How does the covalent bond keep the atoms
           from separating?

11.6    Covalently bonded substances form molecules.  For example, the methane molecule CH4
           (commonly known as natural gas) looks like this.  How many covalent bonds does
           a methane molecule have?

11.7    When large numbers of positively and negatively charged ions collapse on themselves...
            a result of their mutual attractions...they form what is called an ionic lattice.
            Draw a picture of a simple ionic lattice.

11.8     Both ionic and Covalent bonds are strong.  What does this mean?

11.9     When you break an ionic bond, what forces are you attempting to overcome?
            When you break a covalent bond, what forces are you attempting to overcome?



Click and Drag below for answers

11.1    a. Covalent         b. Ionic                c. Covalent    d.  Covalent       e.  BOTH  
           f.   Ionic              g. Covalent          h. Covalent     i.Covalent        j.  BOTH
11.2    Between the two bonded atoms
11.3    The metal atom gives an electron to the non-metal atom.  This produces a
            positively charged metal atom (Cation) and a negatively chargednon-metal atom (Anion)
11.4     As the ions crash towards eachother their potential energy decreases...the energy released
            as heat.
11.5     The "shared" electrons exist between the two atoms.  Although both atoms have no attraction
            for each other, they DO have attraction for the electrons between.  This is a little like
            a peanut butter sandwich where the PB holds the two bread pieces together.
11.6     4 Covalent bonds.  Each attaches one hydrogen atom to the center carbon atom
            to form the methane molecule.
11.7     Click here for an example....
11.8     Breaking an ionic bond involves pulling two oppositely charged ions apart.  Your are
            overcoming what's known as "electrostatic attraction."
            Breaking a covalent bond involves pulling a positive atom away from the electrons in the
            covalent bond which are negatively charged. You are again overcoming the
            electrostatic attraction each atom has for the bonding electrons.
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Wednesday January 24, 2024    Day 12
Ionic Compounds, Polyatomic Ions and Formula Units
Textbook Readings:

3.3: Representing Compounds: Chemical Formulas and Molecular Models

3.4: An Atomic-Level Perspective of Elements and Compounds


 Course Lectures

2.4  pdf  Video*  Chemical Nomenclature 
What is an Ion?

 		What is a Polyatomic Ion?
Introduction to Writing Ionic Formulas

 		Writing Formulas with Polyatomic Ions
Objectives

1. Determine monatomic ion charges for various elements using your periodic table.
2. Provide names and formulae for all polyatomic ions (see problems below).
3. Correctly write neutral chemical formulae for all ionic combinations.




Homework Problems

12.1   In your own words, what is a Cation?   What is an Anion?  What is a monatomic ion?

12.2   As ions, what is the charge (usually) on each of the following elements?
          a. oxygen      b. magnesium     c. fluorine     d. postassium      e. silver      f. sulfur      g. aluminum

12.3    Write the correct chemical formulae for the following imaginary
           cation and anion combinations.
          a. X+1   Y-1            b. A+2   B-1            c. M+1   N-3             d. K+3    L-2         e. X+3   Y-1  
          f. A+2    B-3            g. M+3  N-2

12.4    Write the correct chemcal formulae for the following cation and anion combinations.
          d. K+    O-2            b. Al+3  Cl-1             c. Ca+2    N-3            d. Al+3  O-2
          e. Li+1   F-1            f. Sr+2   Br-1            g. Na+1   N-3        

12.5   Below are the 15 polyatomic ions you must memorize (Names, formulae and charges)
          For each, re-write the formula followed by the ion's name? Practice!
               a. NH4+          b. H3O+         c. CH3COO-        d. CN-                e. OH-           
               f.  ClO3-          g. ClO4-          h. NO3-                 i. MnO4-           j. CO3-2        
               k.  HCO3-      l.   Cr2O72-     m.  PO43-             n. SO42-             o. SO32-
           
12.6    Write the correct chemical formulae for the following cation and anion combinations.
           Remember the cation is always written first.

            a. Chloride ion and ammonium ion           b. calcium ion and carbonate ion
            c.  Sodium ion and dichromate ion            d. potassium ion and phosphate ion
            e. Calcium ion and hydroxide ion              f.  amonium ion and bicarbonate ion
            g. Aluminum ion and sulfate ion.               h. Aluminum and hydroxide

Click and Drag below for answers

12.1 A cation is a positively charged atom where the number of  +protons in the nucleus is greater than the number of -negatively charged electrons.  An anionis a negatively charged atom where the number of  +protons in the nucleus is less than the number of -negatively charged electrons. A monatomic ion is a single atom with a charge as opposed to a polyatomic ion that is a molecule with a charge.

12.2  a. -2    b. +2    c. -1    d. +1    e. +1    f. -2     g. +3

12.3  a. XY     b. AB2      c. M3N      d. K2L3      e. XY3      f. A3B2     g. M2N3

12.4  a. K2O      b. AlCl3      c. Ca3N2      d. Al2O3      e. LiF      f. SrBr2      g. Na3N

12.5   a. Ammonium       b. hydronium       c. acetate           d. cyanide                e. hydroxide
          f. chlorate             g. perchlorate      h. nitrate            i. permanganate      j. carbonate
          k. bicarbonate      l.  dichromate      m. phosphate      n. sulfate                 o. sulfite  

12.6    a.  NH4Cl             b. CaCO3          
           c. Na2Cr2O7         d. K3PO4              
           e. Ca(OH)2           f.  NH4HCO3
           g.  Al2(SO4)3         h.  Al(OH)3 


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Thursday January 25, 2024   Day 13
Ionic and Molecular Nomenclature
Textbook Readings:

3.5: Ionic Compounds: Formulas and Names

3.6: Molecular Compounds: Formulas and Names

3.7: Summary of Inorganic Nomenclature

 Course Lectures

2.4  pdf  Video*  Chemical Nomenclature
Naming Ionic Compounds

 		Naming Covalent Molecular Compounds


Objective

1.  Given an ionic chemical formula, correctly write its name
2.  Given an ionic name, correctly write its chemical formula.
3.  Given a molecular chemical formula, correctly write its name.
4.  Given a molecular name, correctly write its chemical formula.


Homework Problems

 Click here for a list of monatomic transition metal ions you must memorize.

13.1   Write the name of each of the following ionic compounds
           a. NaCl        b. CaBr2       c. Mg2O3       d. ZnS      e. BaI2

13.2   Write the chemical formula for each of the following ionic compounds.
           a. cesium fluoride                        b. silver chloride               c. magnesium iodide   
           d.  barium oxide                           e. aluminum oxide             f. lithium bromide

13.3    What is the charge on both ions in each of the following chemical formulae?
            a. CuCl                    b. CuCl2                 c. HgCl2                 d. Hg2F2
            e.  Mg(NO3)2           f.  FeSO4                g. FePO4                h. Cr(NO3)2

13.4    Write the name of each of the following ionic compounds
            a. CuCl                    b. CuCl2                 c. HgCl2                    d. Hg2F2
            e.  Mg(NO3)2           f.  FeSO4                g. FePO4                h. Cr(NO3)2

13.5    Write the name for each of the following molecular formulae
            a. H2O       b. CH4         c. C2H2       d. CO        e. CO2    
            f. BCl3        g. C3H8       h. SiH4        i. SeCl2      g. SO3

13.6     What is the chemical formula for each of the following compounds?

             a. sodium fluoride                        b. magnesium nitrate         c. nitrogen trihydride
             d. phosphorus pentachloride      e. disulfur decafluoride      f. copper (II) nitrate
             g. iron (II) carbonate                   h. nitrogen monoxide         i. chromium (II) phosphate
             j. chlorine trifluoride                  k. cobalt (II) sulfate            l.  calcium cyanide


Click and Drag below for answers

13.1    a. sodium chloride        b. calcium bromide         c. magnesium oxide   
          d. zinc sulfide                 e. barium iodide

13.2    a.   CsF   b. AgCl    c. MgI2    d. BaO    e. Al2O3    f. LiBr

13.3    a. Cu: +1  Cl: -1          b. Cu: +2  Cl: -1           c. Hg: +2   Cl: -1         d. Hg: +1     F: -1
           e. Mg: +2   NO3: -1     f. Fe: +2   SO4: -2        g. Fe: +3   PO4: -3       h.   Cr: +2   NO3: -1
  
13.4    a. copper (I) chloride   b. copper (II) chloride   c. mercury (II) chloride   d. mercury (I) fluoride
           e. magnesium nitrate    f. iron (II) sulfate        g. iron (III) phosphate      h. chromium (II) nitrate

13.5    a. dihydrogen monoxide    b. carbon tetrahydride   c. dicarbon dihydride  d. carbon monoxide
           e. carbon dioxide     f. boron trichloride   g. tricarbon octahydride    h. silicon tetrahydride
           i. selenium dichloride    g. sulfur trioxide

13.6    a. NaF    b. Mg(NO3)2     c. NH3       d. PCl5         e.  S2F10         f. Cu(NO3)2        g. FeCO3
           h. NO     i. Cr3(PO4)2       j. ClF3      k. CoSO4      l. Ca(CN)2
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Friday January 26, 2024   Day 14
Formula Mass and Compound Molar Mass Calculations
Textbook Readings:

Formula Mass and the Mole Concept

 Course Lectures

How to Calculate Molar Mass Practice Problems



 		Grams to Molecules and Molecules to Grams Conversion


Objectives

1. Calculate molar masses (a.k.a. molecular mass) for ionic and molecular compounds
2. Use molar mass to convert mass to moles AND moles to grams
3.  Use molar mass to determine moles, molecules and atom numbers

Homework Problems

When calculating "Molar Mass", always use the most accurate periodic table available
and do NOT round  the atomic mass values beforehand.

14.1  What is the difference between a formula mass and a molecular mass (See reading above)

14.2  For each of the following, calculate the formula mass (molar mass)
          a. NaCl                                   b. AlCl3                     c. Ca3N2                             d. K2S
          e. Fe(NO3)2                           f. Cr(OH)2                g.  mercury (II) nitrate      h.  sodium acetate
 
14.3   Calculate the  molecular mass (molar mass) for each of the following molecules.

          a. carbon dioxide                  b. dihydrogen monoxide          c. sulfur hexafluoride
          d. chlorine trifluoride           e. tetracarbon decahydride    f.  methane

14.4  Use dimensional analysis to convert 100.0 grams of carbon dioxide into:
          a. moles of carbon dioxide           b. molecules of carbon dioxide    c. atoms of oxygen

14.5   Use dimensional analysis to convert 80.0 μg of water into:
          a. moles of water                               b. molecules of water                        c. atoms of oxygen

14.6   Convert each of the following into moles:
          a. 50.0 grams NaCl                   b. 0.505 g Ca3N2              c. 1.22 x 10-5 g AlCl3    
          d.  1.0 kg K2S                            e.  1.895 g ClF3                f.  8.55 mg  CO

14.7   Convert each of the following mole amounts into grams of the compound:

    a.  1.55 moles aluminum metal         b. 1.55 moles Al2O3                       c. 1.55 moles Al(NO3)3
    d.  2.33 x 10-3 moles iron metal         e.  2.33 x 10-3 moles Fe(OH)2       f. 2.33 x 10-3 moles   Fe2(CO3)3       

 
Click and Drag below for answers

14.1  Both are in fact "Molar Mass" ... that is the mass of a mole of the compound.  Molecular mass is the term used to describe Molar mass for non-metal/non-metal compounds that are covalently bonded.  Formula Mass is used to describe Molar Mass for ionic compounds where a single "molecule" doesn't exist.

14.2   a. 58.442770 g/mol       b. 133.340538 g/mol     c. 148.247400 g/mol     d. 110.261600 g/mol
          e. 179.854800 g/mol      f.  86.010780 g/mol      g. Hg(NO3)2   324.599800 g/mol
          h. NaCH3COO   82.033790 g/mol 
        
14.3   a. 44.009500 g/mol     b. 18.015280 g/mol    c. 146.055419 g/mol     d. 92.448210 g/mol
          e. 58.122200 g/mol      f. 16.042460 g/mol

14.4  a. 2.27223 moles CO2               b. 1.36788 x 1024 CO2 molecules      c.  2.736 x 1024 Oxygen atoms

14.5  a. 4.44067 x 10-6 moles H2O     b. 2.67417 x 1018 H2O  molecules     c.  2.67417 x 1018 Oxygen atoms

14.6  a. 0.856 moles NaCl     b. 3.41 x 10-3 moles Ca3N2     c. 9.15 x 10-8 moles AlCl3   
         d.  9.1 moles K2S          e.   0.02050 moles ClF3           f.   0.305 mmole   CO

14.7  a.  41.8 g Al      b.  158 g Al2O3              c.  330.   g Al(NO3)3
         d. 0.130 g Fe     e. 0.209 g  Fe(OH)2      f.  0.680 g Fe2(CO3)3


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