Unit 4 Quiz 2 – Moles and
Formulas
The Review!
(you need a periodic table, piece of
scrap paper, and calculator)
Review Game Rules
• I will ask a question to the class.
• Each participant (that’s you) writes down the
answer silently.
– Not each group…each individual.
• After a few moments, I will say, “Compare
answers.”
• Each of you will look at what the other wrote.
Review Game Rules
• Did you each get the right answer?
– 2 points.
• Did one of you get the right answer?
– 1 point.
• Neither of you?
– For shame. 0 points.
– And eternal guilt.
Review Game Rules
• The List of Do Nots:
– Do not talk to each other, make noises, gesture,
give answers (my discretion here) between when
the question has been read and when I say,
“Compare answers.”
• Doing so will result in a disqualification for that round.
Don’t believe me? Try it.
– Do not fall asleep when I’m getting scores.
• If you’re not paying attention, I’m not giving you points.
Review Question 1
• How many representative particles are in a
mole of grilled cheese sandwiches?
• 6.02 x 1023 grilled cheese sandwiches.
Review Question 2
• What’s the official name for 6.02 x 1023?
– Avogadro’s Number.
Review Question 3
• If you have a mole of osmium (Os), you have
6.02 x 1023 what?
– Atoms.
Review Question 4
• If you have a mole of water (H2O), you have
6.02 x 1023 what?
– Molecules.
Review Question 5
• If you have a mole of diphosphorus pentoxide
(P2O5), you have 6.02 x 1023 what?
– Molecules.
Review Question 6
• If you have a mole of sodium oxide (Na2O),
you have 6.02 x 1023 what?
– Formula units.
Review Question 7
• What’s the formula for ammonium nitrate?
– NH4NO3
Review Question 8
• What the name for Pb3(PO4)4?
– Lead (IV) phosphate.
Review Question 9
• How many liters does a mole of H2O (g) take
up? Assume standard temperature and
pressure (STP).
• 22.4 L.
Review Question 10
• How many liters does a mole of H2O (l) take
up? Assume standard temperature and
pressure (STP).
– Cannot determine directly.
– HOWEVER, give your team 3 bonus points if you
said that a mole of H2O is 18.0148 g, which, given
water’s density, is 18.0148 mL, which is 0.0180148
L.
Review Question 11
• How many liters does a mole of Fr (s) take up?
Assume standard temperature and pressure
(STP).
– Cannot determine directly.
Review Question 12
• BONUS NON-CHEMISTRY QUESTION
• You may wager any/all of your points.
• Category: Aviation History
• In May of 1927, Charles Lindbergh became the
first to fly solo across the Atlantic. What was
the name of his airplane?
– The Spirit of St. Louis
Review Question 13
• BONUS NON-CHEMISTRY QUESTION
• You may wager any/all of your points.
• Category: Board Games
• Chess has its origins in a game called
chaturanga. Which country first started
playing chaturanga?
– India.
Review Question 14
• Suppose you’re asked to convert grams to
molecules. To what do you convert grams
first?
– Moles.
Review Question 15
• Assuming you actually are converting a
quantity of grams to moles, what do you do to
get moles?
– Divide by the molar mass.
Review Question 16
• About how many moles are in 88.0 grams of
carbon dioxide (g)?
– About 2 (or 1.99) moles.
Review Question 17
• Now that you have a mole quantity, how do
you get to molecules?
– Multiply by Avogadro’s Number (6.02 x 1023).
Review Question 18
• And if you have 1.99 mol CO2, how many
molecules is that?
• 1.198 x 1024 molecules CO2.
Review Question 19
• But if you had 1.99 mol CO instead, how many
molecules would that be?
• 1.198 x 1024 molecules CO.
Review Question 20
• And how much space would that 1.99 mol CO
take up?
• 44.576 L.
Review Question 21
• BONUS NON-CHEMISTRY QUESTION
• You may wager any/all of your points.
• Category: Presidential Quantities
• In the Gettysburg Address, President Lincoln
addressed the crowd first by saying, “Four
score and seven years ago…”. How many is a
score?
– 20. The speech was given in 1863; he was
referring to 1776 – 87 years prior.
Review Question 22
• How are ionic compounds written – as
empirical formulas, molecular formulas, or
both?
– Empirical formulas.
Review Question 23
• Any hydrate problem requires you to find two
quantities in moles. What are those two
quantities?
– Moles of water evaporated.
– Moles of anhydrous salt.
Review Question 24
• Once you find those two quantities (mol H2O,
mol [salt]), what do you do with them?
– Divide mol H2O by mol [salt].
Review Question 25
• Are hydrate formulas always written
empirically or molecularly?
– Empirically.
Review Question 26
• When finding an empirical formula, what’s the
next step after converting masses to moles?
– Divide each mol quantity by the smallest mol
quantity (then multiple to get rid of decimals if
necessary).
Review Question 27
• Suppose you find an empirical formula to be
CH2O. If the molecular formula is 90 g/mol,
what’s the molecular formula?
– C3H6O3.
Review Question 28
• Suppose you find an empirical formula to be
CH4. If the molecular formula is 16 g/mol,
what’s the molecular formula?
– CH4.
Review Question 29
• For a hydrate formula, what would be the
appropriate inequality?
• Moles of Water ____ Moles of Anhydrous Salt
A. <
B. ≤
C. =
D. >
E. ≥
– Choice E (≥).
Review Question 30
• BONUS NON-CHEMISTRY QUESTION
• You may wager any/all of your points.
• Category: Aviation History
• Capt. Paul Tibbets was partially responsible for
killing or injuring 135,000 people. Who was
he?
– The captain of the Enola Gay, the aircraft that
dropped the atomic bomb on Hiroshima in 1945.