WorksheetsMolar Mass and Percent Composition
Total questions: 13
Worksheet time: 37mins
Name
Class
Date
1.
What is the molar mass of CO2?
a)
12 g/mol
b)
16 g/mol
c)
32 g/mol
d)
44 g/mol
2.
Find the percentage composition of Mg in Mg3(PO4)2.
a)
27.48% Mg
b)
43.11% Mg
c)
16.00% Mg
d)
12.63% Mg
3.
What is the molar mass of table salt (NaCl)?
a)
116.886 g/mol
b)
35.453 g/mol
c)
22.990 g/mol
d)
58.443 g/mol
4.
Which of the following is NOT needed to calculate percent composition?
a)
Mass of specific element
b)
Molar Mass
c)
Avogadro's Number
d)
Division
5.
What is the percent by mass of sodium in NaCl?
a)
39%
b)
61%
c)
35%
d)
65%
6.
What is the mass percentage of Carbon in Carbon dioxide (CO2)?
a)
27.27%
b)
42.86%
c)
72.73%
d)
72.72%
7.
What are the units in molar mass?
a)
grams
b)
moles
c)
moles/gram
d)
grams/mole
8.
The molar mass of an element is equal to its...
a)
Atomic mass
b)
Atomic number
c)
Oxidation number
d)
Valence electrons
9.
Which of the following statements is NOT true?
a)
Molar mass is molecular mass
b)
Molar mass is the sum of the number of all atoms in one molecule
c)
Molar mass is the sum of the weight of all the atoms in the molecule
d)
You don't need atomic numbers when calculate molar mass
10.
What is the molar mass of fluorine gas, F2?
a)
18.998 g/mol
b)
38 g/mol
c)
9 g/mol
d)
18 g/mol
11.
Find the percentage composition of Mg in Mg3(PO4)2.
a)
27.48% Mg
b)
43.11% Mg
c)
16.00% Mg
d)
12.63% Mg
12.
Which list of number of atoms in MgF2 is right?
a)
Mg : 1-- F : 1
b)
Mg : 1 -- F : 2
c)
Mg : 2 -- F : 1
d)
Mg : 0 -- F : 1
13.
In the formula (NH4)3PO3, how many atoms of hydrogen are there?
a)
1
b)
4
c)
3
d)
7
e)
12
100 %
