Q1 M5 SHS_GENERAL-CHEMISTRY-1_Empirical-and-Molecular-Formula.pdf

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Writer: Coleen Michelle L. Magalong
Cover Illustrator: Christine Ann G. Faraon
General Chemistry 1
First Quarter-Module 5:
Empirical and Molecular Formula
Department of Education
National Capital Region
SCHOOLS DIVISION OFFICE
MARIKINA CITY

This module was designed and written with you in mind. It is here to help you
master the concepts and ideas in Chemistry. The scope of this module permits it to
be used in many different learning situations. The language used recognizes the
diverse vocabulary level of students. The lessons are arranged to follow the standard
sequence of the course.
Learning Competencies
 Calculate the empirical formula from the percent composition of a
compound (STEM_GC11PCIf-32).
 Calculate molecular formula given molar mass (STEM_GC11PCIf-33).
After going through this Lesson, you are expected to
1. define percent composition, empirical, and molecular formula;
2. determine the formula mass of a compound;
3. describe steps in calculating percent composition of a compound; and
4. explain the steps in determining the empirical formula of a compound.
Read each questions carefully. Choose the letter of the best answer then write your
answers on a separate sheet of paper.
1. Which of the following gives the actual number of atoms present in a
chemical compound?
What I Know
What I Need to Know
2. Which of the following is an example of a molecular formula?
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3. Which of the following is an example of an empirical formula?
4. What is the correct molecular weight of NH
3
?
A. 17 g/mol
B. 18 g/mol
C. 19 g/mol
D. 20 g/mol
5. What is the molar mass of barium perchlorate, Ba (ClO
4
)
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? 6. A compound has a molecular formula of C
12
H
24
O
6
. What is its empirical
formula?
7. In a 100 g sample of a substance, 85.6% is carbon and 14.4% is Hydrogen.
How much carbon in grams is in the sample of substance?
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