HOLD UP YOUR BOARD! Chapter 7 Review game
HOLD UP YOUR BOARD!
Chapter 7 Review game
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Rules• Use the same periodic table.• Use the mass as written on the periodic
table• Round up your calculations to 2 decimal
points• Follow significant rule for your final
answer• Do the calculation on the board and circle
your answer• All your units must be included for full
credit! • If you get a questions wrong, you are out
until you get the “COME BACK” questions correct.
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Rules
•Everyone will need to show their own work on a separate sheet of paper for a 1 HW credit.
•The winning team will receive 5pt extra credit on the test.
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Question #1
•Find the number of molecules or ions
2.00 mol Fe 3+
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2.00 mol
1 mol
6.02 x 1023 ions
= 1.20 x 1024 ions
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Question #2
Find the number of moles.
3.01 x 1023 molecules
of H2O
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1 mol 3.01 x 1023 molecules
= 0.500 mol H2O
6.02 x 1023 molecules
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Question #3
•Find the number of moles of sodium ions Na+
Na2CO3
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2 mol of Na+
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Question #4
Find the number of sodium ions
3.00 mol Na2CO3
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3.00 mol Na2CO3
1 mol Na2CO3
6.02 x 1023 ions2 mol Na+
1 mol Na+
= 3.61 x 1024 atoms
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Question #5
Find the mass in grams
4.30 x 1016 atoms of He
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1 mol 4.30 x 1018
atoms
= 2.86 x 10-7 g He
6.02 x 1023 molecules 1 mol
4.00 g
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COME BACK!!!!!
Find the mass in grams
4.01 x 1023 atoms of Ca
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1 mol 4.01 x 1023
atoms
= 26.7 g Ca
6.02 x 1023 molecules 1 mol
40.08 g
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Question #6
What is the percent composition of Na in
NaCl?
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NaCl = 22.99 g Na
22.99g Na + 35.45g Cl = 58.44 g NaCl
22.99 g Na x 100 % 58.44 g NaCl
= 39.34% Na
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Question #7
Determine the empirical formula of a compound that
is 63.50% Ag,
8.25% N28.25% O.
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63.50g Ag = 0.59 mol Ag8.25 g N = 0.59 mol N28.25 g O = 1.77 mol O
Divide all the mol by 0.59.
AgNO3
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Question #8
Determine the empirical formula of a compound
that is 56.34% P
And the rest is O.
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56.34g P = 1.82 mol P43.66 g O = 2.73 mol O
Divide all the mol by 1.82.PO1.5
Multiply by 2 for whole number ratio
P2O3
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Question #9
A compound has an empirical formula of CH. Its molecular mass is 78 g/mol. What is its molecular formula?
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C = 12.01 g/mol H = 1.01 g/mol 13.02 g/mol
78 g/mol13.02 g/mol = 5.99 = 6
6 (CH) = C6H6
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Question #10
The empirical formula is P2O5. Its molar mass is 284 g/mol. Determine
the MOLECULAR formula.
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P x 2 = 30.97 g/mol x 2O x 5 = 16.00 g/mol x 5 141.94 g/mol
284 g/mol141.94 g/mol = 2
2 (P2O5) = P4O10