Accelerated Chemistry

Atomic Structure and Mole Conversions

Chemist: ______

Counting Atoms Worksheet # 1

1. Determine the subatomic particles in each of the following::

p+ / e- / n° / Atomic # / Mass #
27Al
Br
Fe
Ca+2
O-2

2. Complete the following table:

p+ / e- / n° / Atomic # / Mass #
K+1 / 40
12 / 12
36 / 53 / 91
-1 / 10 / 19

3. Carbon consists of 98.89% 12C (12.00000), and 1.110% 13C (13.00335). Calculate the atomic weight of carbon to four significant figures.

4. Gallium consists of two natural isotopes, 69Ga (68.9257) makes up 60.40% of the total. Calculate the % abundance and the mass of the other isotope.


5. Calculate the molar mass of

H2SO4 Cu(NO3) • H2O C3H5(OH)3

6. Convert each of the following using the factor-label method:

0.15 moles of Cu to atoms

75.0 g of H2SO4 to moles

2.55 x 1012 atoms of Ca to grams

10.0 g of Na to atoms

0.100 moles of NaOH to grams

7. How many helium atoms would weigh the same number of grams as 6.00 x 1015 carbon atoms?


Worksheet # 2

1.  Label the following chemicals as either elements or compounds.

C Co CO NaCl F2 CaO

2.  Label the following chemicals as atoms, molecules, or formula units.

C Co CO NaCl F2 CaO

3. Iron consists of four natural isotopes:

% isotope exact isotopic mass

5.82 54Fe 53.9696

91.66 56Fe 55.9349

2.19 57Fe 56.9354

0.33 58Fe 57.9333

Calculate the atomic weight of iron to four significant figures.


3. Neon consists of three natural isotopes:

% isotope exact isotopic mass

90.92 20Ne 19.99244

0.257 21Ne 20.99395

Calculate the (a) % abundance, (b) exact isotopic mass, and (c) mass number of the third isotope.

4. Titanium consists of five natural isotopes:

% isotope exact isotopic mass

7.93 46Ti 45.95263

7.28 47Ti 46.9518

5.51 49Ti 48.94787

5.34 50Ti 49.9448

Calculate the (a) % abundance, (b) exact isotopic mass, and(c) mass number of the fifth isotope.


Worksheet # 3

Convert each of the following:

1.  1.00 mol of Al to grams

2.  1.00 mol of Fe to grams

3.  6.022 x 1023 atoms of Ag to grams

4.  4.25 mol of Li to grams

5.  8.075 mol Au to grams

6.  2.57 x 108 mol of S to grams

7.  1.75 x 10-6 mol of Hg to grams

8.  11.5 g of Na to atoms

9.  3.25 x 105 g of Pb to atoms

10.  0.00750 g of Ag to atoms

11.  1.00 x 10-10 g of Au to atoms

12.  This element has a mass # of 197 and a neutron # of 118. How many protons and electrons does this element have? What element is this?

13.  Fe+3 Neutrons =

Protons =

Electrons =

14.  P-3 Neutrons =

Protons =

Electrons =


Worksheet # 4 –Conversion Worksheet

Show work Complete on a separate sheet of looseleaf.

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Accelerated Chemistry

Atomic Structure and Mole Conversions

Chemist: ______

I. Convert to moles:

  1. 12.04 x 1023 atoms He
  1. 3.01 x 1023 atoms Cu
  2. 1 atom S
  3. 98.9 grams Na

II. Convert to mass in grams:

  1. 10.0 moles Na
  1. 2.20 moles Sn
  2. .0003000 mole Au
  3. 1.00 x 107 moles B

III. Convert to # of atoms:

  1. 3.00 moles Ar
  2. 8.50 moles Fe
  3. .00100 mole Na
  4. 1.0 x 10-5 mole Al

IV. Convert to mass in grams:

  1. 6.02 x 1023 atoms Ca
  2. 1.204 x 1023 atoms Bi
  3. 1000 atoms Al
  4. 1 atom Na

V. Convert to # of atoms:

  1. 540 grams Al
  2. 294 grams Au
  3. 2000 grams Mg
  4. 1.00 grams Li

VI. Convert to moles:

  1. 6.0 x 1023 molecules CO2
  2. 34 grams NH3
  3. 9.00 grams H2SO4
  4. 1.00 grams NaCl

VII. Convert to mass in grams:

  1. 5.0 moles NH3
  2. .00200 mole Na2SO4

VIII. Convert to # of molecules

  1. 2.0 moles CO2
  2. 1.00 x 10-3 mole CO

IX. Convert to # of molecules

  1. 22 grams CO2

X. Convert to mass in grams

  1. 3.01 x 1023 molecules SO2

03_WS_Pkt_-_Atoms_-_S Page 7 of 9

Accelerated Chemistry

Atomic Structure and Mole Conversions

Chemist: ______


Worksheet # 5 - Review

Fill in the gaps in the tables below:

1.

Symbol / 39K / +2 / -2
p+ / 25 / 82
n° / 30 / 82
e- / 54 / 18
Mass # / 33 / 207

2.

Symbol / 70Ga / -2 / +2
P+ / 23
n° / 28 / 45 / 136
e- / 36 / 81
Mass # / 197
Atomic # / 86

3. Vanadium consists of two isotopes: 50V (49.9472) is 0.24% and 51V (50.9440) is 99.76%. Calculate the atomic weight of Vanadium.


Worksheet # 5 – cont’d

4. Chromium consists of four isotopes. 50Cr (49.9461) is 4.31%, 52Cr (51.9405) is 83.76%, 54Cr (53.9389) is 2.38% Calculate the % abundance and exact isotopic mass of the other isotope.

5. Calculate the molar mass of:

(a) BaCl2

(b) (NH4)SO4

(c) Mn3(PO4)2 • 4H2O


Worksheet # 5 – cont’d

6. Convert each of the following using factor-label method:

(a) 3.85 grams of FeSO3 to moles

(b) 2.78 x 10-5 moles of P2S5 to grams

(c) 4.702 x 1047 atoms of Au to moles

(d) 4.140 moles of NaH2PO4 to molecules

(e) 5.31 x 1028 molecules of Mg(OH)2 to grams

(f) 152.1 grams of HC2H3O2 to molecules

7. Explain why the mass of a chlorine atom really isn’t 35.45 amu.

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