NAME____________________________
PRE-TEST
MOLES BIG QUIZ
1. A) One mole is defined as the number of _________________ present in 12 grams of
___________________.
B) What is the mass in amu of one formula unit of table salt (NaCl)?__________
C) What is the mass in grams of one mole of NaCl? ____________
2. Give the name of the representative particle for each of the following types of pure
substances.
ELEMENT_________________
IONIC COMPOUND______________________
COVALENT COMPOUND_______________________
3. Calculate the molar mass of Fe2(SO3)3.
4. How many moles of Boron (B) are present in a in a 10.0 gram sample?
5. How many grams of P2O5 are present in 1.35 x 1024 molecules of P2O5?
6. What is the volume in liters of 12.3 grams of S2O6 gas?
7a). Determine the % composition of each element in the compound Sn3(PO4)4
Sn_______%
P________%
O________%
7b)How many grams of Tin (Sn) could be recovered from a 4.00 gram sample of
Sn3(PO4)4?
8. You own a factory, which is polluting the environment by dumping a poisonous
compound into a nearby stream. The EPA is requiring you to identify the compound.
Determine the empirical formula of this compound if it has the following composition:
33.19% Na; 36.03% As; 30.78% O.
9. You own another factory, which is manufacturing a very dangerous and poisonous
alcohol. This alcohol is composed of:
58.82% carbon, 9.81% hydrogen, and 31.37% oxygen.
This alcohol’s actual molar mass is 204 g/mol.
Determine the empirical formula and the actual molecular formula of the alcohol.
10. Borax, a common cleaner has the formula Na2B4O7 XH2O.
When 15.00 grams of Borax is heated, the mass of the solid decreases to 7.92 grams.
A) Create a data table for this information.
B) Why did the mass decrease?
C) What was the mass of the water in the Borax sample? (show your work)
D) What is the percent composition of water in borax?
(show your work – remember: part over whole)
E) What is the value of X? (show your work)