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This is a lesson about electronic configurations and other lessons you can learn. This module is great and it could help us in studying chemistry....

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11 General Chemistry 1 Quarter 1 - Module 2: Chemical Formula of Common Chemical Substances

What I Need to Know?

This module was prepared to direct you on how to interpret the meaning of a given chemical formula as well as to become familiar with the chemical formula of common chemical substances. Knowing the chemical formula of a certain substance, we could explain the composition and the characteristics of that substance. In addition, familiarization on the chemical formula of common substances, we could easily understand the information written on the food and other product labels. In this manner, we could avoid a danger or misused of products due to lack of familiarization to some chemical formulas. One danger could be allergic reaction if a person took a medicine containing a component that is said to be allergen to that person. The scope of this module covers many different learning situations where students could relate their personal experiences on different samples of matter. The language used recognizes the diverse vocabulary level of students. The lessons are arranged to follow the standard sequence of the course. But the order in which you read them can be changed to correspond with the textbook you are now using. After going through this module, you are expected to: 1. recognize the formulas of common chemical substances, (STEM_GC11Mp1a-b-9).

What I Know? (Critic (Criticaal Thin hinking) king) To check your prior knowledge about the topic, and to solicit the questions that you want to know about it, fill in the Know and Want to know components of the Know-Want to know- Learned (KWL) chart properly and correctly. For the Know component, you may write word/s or sentence. For the want to know component, state your responses in interrogative or question form. You may list as many responses as you want for each component. Write your responses on a separate

sheet of paper. Topic Chemical Formula

Know

KWL Chart Want to know

2

Learned

Guide Questions 1. Based from what you have written on the Know component of the chart, what do you know about chemical formula? 2. If you were to think of a question that you want to ask about chemical formula, what question would that be? HOLD ON AMIGO!!! DIRECTION: After you have filled-in the K and W components of the chart and answered the guide questions, answer now the diagnostic assessment below within 10 minutes.

PRE-TEST A. Sentence Completion. Complete each statement with a word/ concept in the blank of the item.

1. The chemical symbol of oxygen is _____. 2. There is/are ____ hydrogen atom/s present in this chemical formula C 6 H 12 O 6 . 3. _____ is shorthand of expressing the types and the number of atoms present in a substance. 4. C is the chemical symbol for ______. 5. There is/are _____ oxygen atom/s in H 2 O. B. Identification. Determine the types and number of atoms in the following chemical formulas. 6. BF 3 7. C 3 H 8 8. K 2 CO 3 9. CH 4 10. CF 4

HOLD ON AMIGO!!! DIRECTION: Rest for 1 minute then you may start reading the lesson 1 below about the characteristics of the Particles of Matter.

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Lesson Chemical Formula 1 Food, medicine and other product labels may sometime confuse you on the ingredients or materials that contain them because these are written in their chemical formula form. These formulas are often alien to us because of our lack of understanding or idea about chemical formula. Most of the time, we associate chemical formulas for scientists or chemists only. That is why some people tend to lose interest on trying to understand the meaning of a chemical formula because to them as ordinary persons, this thing is not important and just a waste of time if they will study it. But because of the changing society coupled with information explosion, it is important to us to grasp an idea on how to interpret a chemical formula, and become acquainted with common formulas which we usually encounter every day. This module will discuss the meaning of a given chemical formula as well as the formula of some common chemical substances.

What’s In? LET US HAVE SOME FUN! Picture Analysis. Analyze the picture below then answer the corresponding guide questions.

Guide Questions 1. What is the picture all about? Why? 2. Which substance is being represented by that structure? (Clue: It is the universal solvent) 3. What is the formula of that universal solvent? Explain your answer. HOLD ON AMIGO!!! DIRECTION: After you analyze the given picture and answered the guide questions, let us proceed to what’s new. Read the direction carefully. 4

What’s New? (Commun (Communicat icat ication) ion) IMPORTANT VOCABULARY WORDS Read the description of important terms that you will encounter in this module. VOCABULARY WORD

MEANING

1. Subscript

A small number written at the lower right corner of a chemical symbol.

2. Chemical symbol

An abbreviation that represents the name of an element.

HOLD ON AMIGO!!! DIRECTION: After finding out the meaning of important terms that you will encounter as you read the next part, make time to read the characteristics of the particles below thoroughly.

What is a Chemical Formula? Chemical Formula If we are to study the meaning of chemical formula, two words are involved namely chemical and formula. Chemical refers to a compound or substance while formula refers to the symbolic expression. Thus, a chemical formula is a symbolic expression of a compound or substance. It is also described as shorthand of expressing the types and the number of atoms in a substance.

What is the Meaning of a Given Chemical Formula? Once again, chemical formula is the shorthand of expressing the types and the number of atoms in a substance. For example, CO 2 is the chemical formula of a substance known as carbon dioxide. But what does this CO2 formula mean? What information can we get from this formula? In this substance based from its formula of CO2 , the said substance is made up of two types of atoms, these are carbon and oxygen. This is because the formula has two different letters that are written in capital form; C and O. The capital letter is known as chemical symbol that represents a certain substance known as element. Let us use the periodic table below to determine the chemical symbol of the elements.

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Molecular Structure of CO 2. The chemical formula also tells the number of each type of atom and the central atom of the molecule specifically if it is not a diatomic molecule. The first chemical symbol written at the right side of the formula tells us that it is the central atom, or the atom located at the center of the molecule. So, for CO 2 , since C is the first letter of the chemical formula, the C which is the carbon atom is the central atom. If the letter is the chemical symbol that represents an element, the subscript represents the number of atom in the chemical formula. In CO2 , the subscript of oxygen is 2 while carbon is 1. Even though there is no number 1 indicated after letter C in CO 2 , it is presumed that there is one. So the number after the letter refers to its number of atoms.

Chemical Formula of Carbon dioxide

So let us take HCl as another example. Determine the atoms represented by chemical symbols that make up the formula, and determine the number of each atom.

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In the chemical formula HCl, there are two elements which are combined together. These are hydrogen represented by the chemical symbol of H and chlorine which is represented by the chemical symbol of Cl. Note that the l in Cl is not expressed in capital letter. This means that the letter l is part of Cl and not separate chemical symbol. After determining that HCl has two combined chemical symbols. The next step is to identify the number of atoms of each element that make up the chemical formula. So in HCl, since there is no number written after H, we presumed that there is only 1 H. The same thing with Cl, there is only 1 atom of Cl in the formula. In short, there is only 1 Hydrogen atom and 1 Chlorine atom.

HOLD ON AMIGO!!! Did you understand what you have read about chemical formula? If yes, let us proceed to the mini-performance task. You are about to perform the procedure as instructed in the Mini-performance task. Read and follow the procedure carefully. Good luck!

Mini-Performance Task (Col (Collaborat laborat laboration) ion) Activity 1 – Chemical Formula and Molecular Structure Procedure 1. Determine the common name, the types and number of atoms, and the molecular structure of the given chemical formula in each item. 2. Fill-in the table with correct information.

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Data and Results Chemical Common Formula Name 1.

NaCl

2.

NH 3

3. 4.

Type of Atoms

Number of Each Atom

Molecular Structure

C 12 H 22O 11 CH 4

5.

C 9H 8O 4

6.

NaOH

QUESTIONS 1. What is the common name of each substance? 2. How is chemical symbol different form a chemical formula?

What I Have Learned? (Critic (Criticaal Thin hinking) king) You have to fill in the L component of the KWL chart to generalize the things they have learned about the topic. KWL Chart Topic Know Want to know Learned Chemical Formula I have learned that ….

HOLD ON AMIGO!!! After you have filled-in the L component of the chart, proceed now to the what I can do. 9

What I Can Do? (Ch reativi Ch Chaaracter and Creativi ativity ty) WORK IN PROGRESS You may choose to any of the added task to you. 1. Research on the active ingredient or chemical present in plant extract found in the Philippines that has antiseptic property. Determine the chemical formula of the active ingredient. 2. Formulate a right formula to successful life? How about to covid-free life?

HOLD ON AMIGO!!! Congratulations Mi Amigo! You are almost done in this lesson. Let us do the last part which is the assessment.

Assessment (Critic (Criticaal Thinking) FORMATIVE ASSESSMENT A. Sentence Completion. Complete each statement with a word/ concept in the blank of the item.

1. _____ is shorthand of expressing the types and the number of atoms present in a substance. 2. The chemical symbol of carbon is _____. 3. There is/are ____ nitrogen atom/s present in this chemical formula NH 3 . 4. O is the chemical symbol for ______. 5. There is/are _____ hydrogen atom/s in C 6 H 12 O 6 .

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B. Identification. Determine the common name, the types and number of atoms, and the molecular structure of the given chemical formula in each item. Chemical Common Type of Number Molecular Structure Formula Name Atoms of Each Atom 1.

CaCO 3

2.

CaO

3.

C 2 H 5 OH

HOLD ON AMIGO!!! Congratulations Mi Amigo!!! We are done in this module. You may now proceed to the next module. See you next time.

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REFERENCES Mendoza E. and Religioso T. (2008). Chemistry Laboratory Manual. Phoenix Publication Mendoza E. (2003). Chemistry Textbook. Phoenix Publication

Acknowledgements Writer: Gary R. Ramos, MAT-GS Editors: Ma. Teresa M. Chico- PSDS, Rosalina Aranzamendez- PSDS and Ma. Victoria Santos- PSDS Reviewers: Amalia C. Solis- EPS, Rebecca M. Roxas- EPS and Lucita A. Gener- EPS Management Team: Maria Magdelema M. Lim - Schools Division SuperintendentManila, Aida H. Rondilla- Chief Education Supervisor, Lucky S. Carpio- EPS and Lady Hannah C. Gillo, Librarian II- LRMS 12

ANSWER SHEET Module 2 – Chemical Formula Name: ______________________________ Grade/ Sec. ____________________ Score: ___ Teacher: ____________________________ School: _________________________ Date: ____ General Direction: Write your answers here from Pre-Test to Post-Test including the answers in the activities. Detach and submit this part to your teacher upon his/her direction which usually after you have completed this module. KWL CHART Topic Chemical Formula

Know

PRE-TEST Sentence Completion 1. 2. 3. 4. 5. POST-TEST Sentence Completion 1. 2. Identification Chemical Common Formula Name 1.

CaCO 3

2.

CaO

3.

Want to know

Learned

Identification 6. 7. 8. 9. 10.

3. 4.

5.

Type of Atoms

Number of Each Atom

C 2 H 5 OH

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Molecular Structure

Activity 1 – Chemical Formula and Molecular Structure Data and Result Chemical Formula 1.

NaCl

2.

NH 3

3. 4.

Common Name

Type of Atoms

Number of Each Atom

Molecular Structure

C 12 H 22O 11 CH 4

5.

C 9H 8O 4

6.

NaOH

Answer to Questions 1.________________________________________________________________________________ __________________________________________________________________________________ 2.________________________________________________________________________________ __________________________________________________________________________________

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