Worksheets2A: Mass, % Composition, Empirical/Molecular Formula
Total questions: 15
Worksheet time: 30mins
Name
Class
Date
1.
Calculate the mass of calcium carbonate. Make sure to have the correct formula.
a)
100.1 g/mol
b)
68.34 g/mol
c)
300.3 g/mol
d)
124.1 g/mol
2.
What are the units for molar mass?
a)
grams
b)
amu
c)
grams/mole
d)
liters
3.
What is the mass of one mole of aluminum chloride (remember to determine the correct formula first)?
a)
62.435g
b)
116.399g
c)
133.341g
d)
97.888g
4.
Find the percentage composition of Mg in Mg3(PO4)2.
a)
27.75% Mg
b)
23.57% Mg
c)
48.68% Mg
d)
13.45% Mg
5.
Find the percent composition of each element in N2S2 .
a)
69.6% N, 30.4%S
b)
15.2% N, 84.8% S
c)
30.4% N, 69.6% S
d)
65.2% N, 34.8% S
6.
Find the percent composition of hydrogen in (NH4)2S.
a)
11.8%
b)
41.1%
c)
47.1%
7.
You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements
a)
SO
b)
SO2
c)
SO3
d)
SO4
8.
What is the molecular formula if the empirical formula is C2H5 and the molecular molar mass is 58.14 g/mol?
a)
C2H5
b)
C4H10
c)
C1H2.5
d)
C4H8
9.
A formula with the lowest whole # ratio of elements in a compound is called
a)
empirical formula
b)
chemical formula
c)
covalent formula
d)
molecular formula
10.
A chemical formula that shows the actual # of atoms present in a compound is called_________
a)
ionic formula
b)
covalent formula
c)
empirical formula
d)
molecular formula
11.
Which of the following is the correct empirical formula for C4H10
a)
C2H5
b)
CH2.5
c)
C8H20
d)
C4H10
12.
A substance has a molecular formula of C8H10N4O2. The empirical formula is
a)
CHNO
b)
C2H6N2O
c)
C4H5N2O
d)
C9H7N3O
13.
Determine the empirical formula for a compound with 87.1% Ag and 12.9% S.
a)
AgS2
b)
Ag3S5
c)
Ag2S
d)
Ag4S2
14.
Whats the empirical formula of a molecule containing 18.7% of Lithium, 16.3% of Carbon and 65.0% of oxygen?
a)
CO2Li3
b)
Li2CO3
c)
Li3CO2
d)
LiCO5
15.
A compounds is made up of 30% nitrogen and 70% sulfur. The molar mass of the compound is 92 g/mol. What is the molecular formula for the compound?
a)
NS
b)
N2S2
c)
NS2
d)
N2S
100 %
