GENERAL CHEMISTRY_Q1_Mod6_Writing and Naming the Chemical Formula of Compounds.pdf

www.shsph.blogspot.com 11 General Chemistry 1 Quarter 1 - Module 6 Writing and Naming the Chemical Formula of Compounds w...

www.shsph.blogspot.com 11 General Chemistry 1 Quarter 1 - Module 6 Writing and Naming the Chemical Formula of Compounds www.shsph.blogspot.com What I Need to Know? This module was prepared to train you on how to write the chemical formula of a given compound given its chemical name, or to write the chemical name of a compound given its chemical formula. Knowing the process of writing the chemical formula or chemical name of compounds will make our work easily particularly among professions where chemicals are involved. In addition, familiarization on the chemical formula and chemical name of compounds, we could easily understand the information written on the labels indicated on our purchased products. In this manner, we could avoid a danger or misused of products due to lack of familiarization to chemical formula and chemical name of various compounds. The scope of this module covers many different learning situations where students could relate their personal experiences on different compounds. 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. represent compounds using chemical formulas, structural formula and models, (STEM_GC11AMlc-e-21). 2. name compounds given their chemical formula and write the chemical formula given the chemical name of the compounds, (STEM_GC11AMlc-e- 23). What I Know? (Critical Thinking) 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. KWL Chart Topic Know Want to know Learned Chemical Formula and Chemical Name 2 www.shsph.blogspot.com Guide Questions 1. Based from what you have written on the Know component of the chart, what do you know about chemical formula and chemical name? 2. If you were to think of a question that you want to ask about chemical formula and chemical name, 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 formula of carbon tetrahydride is _____. 2. There is/are ____ hydrogen atom/s present in this chemical formula NH 3. 3. The chemical name of NO 3 is _______ 4. Cl is the chemical symbol for ______ 5. The structural formula of NO 3 is _______ B. Identification. Write the chemical formula of the compound in each item given its chemical name or vice-versa. 6. CO 7. MgCl 2 8. NO 2 9. Nitrogen trichloride 10. Calcium oxide HOLD ON AMIGO!!! DIRECTION: Rest for 1 minute then you may start reading the lesson 1 below about the chemical formula and chemical name of compounds. 3 www.shsph.blogspot.com Lesson Chemical Formula and Chemical 1 Name of Compounds Compounds may often very strange to us because of our lack of understanding or idea about them especially if they are expresses in their chemical formula and chemical name. The chemical formula and chemical name are always written in the food, medicine and other product labels. But being familiar on writing the chemical formula and chemical name of various compounds is not sole responsibility of those who work in chemical-related industries but rather it is a skill that a person must learn. This module will discuss the method of writing the chemical formula and chemical name of a given compound considering the type of chemical bond exist in the said compound properly and correctly. What’s In? LET US HAVE SOME FUN! Analysis. Analyze the figures below then answer the corresponding guide questions. BF3 Figure A Figure B Guide Questions 1. What are the two figure all about? 2. What chemical symbols do you see in both figures? 3. How is figure A different from figure B? 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 www.shsph.blogspot.com What’s New? (Communication) IMPORTANT VOCABULARY WORDS Read the description of important terms that you will encounter in this module. VOCABULARY WORD MEANING 1. Valence Electron The electron located at the outermost shell or energy level. 2. Intramolecular force The force that binds the atoms together in a molecule or compound. 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 writing chemical formula and chemical name of compounds below thoroughly. What is Chemical Formula, Chemical name and Structural Formula? Chemical Formula, Chemical Name and Structural Formula From our previous lesson, we have described chemical formula as a symbolic expression of a compound or substance. It is also defined as shorthand of expressing the types and the number of atoms in a substance. Chemical name is the scientific name given to a chemical in accordance with the nomenclature system developed by the International Union of Pure and Applied Chemistry. While structural formula is a graphical representation of the molecular structure showing how the atoms are possibly arranged in the real three-dimensional space. 5 www.shsph.blogspot.com How to write the Chemical Formula, Chemical Name and Structural Formula of Compounds? Compound This is a substance which is made up of two or more atoms joined together by a chemical bond. Compounds may be classified into two based from the nature of the atoms that make up them, and the type of intramolecular bond that exist between atoms. The two classification of compounds are ionic compound and covalent compound. The ionic compound is formed between a metal atom and a nonmetal atom, and the type of intramolecular bond exist between atoms is ionic bond due to the presence of ionic charges. Example of this is sodium chloride which is made up of metal sodium and nonmetal chlorine. Na+1 + Cl-1 Na 1 Cl 1 or NaCl Sodium Chlorine Sodium chloride The covalent compound is formed between two or more nonmetal atoms, and the type of intramolecular bond that exist between atoms is covalent bond. Example of this is Carbon tetrachloride. Cl C + Cl Cl C Cl Cl Carbon Chlorine Carbon tetrachloride So, in writing the chemical formula, structural formula as well as the chemical name of a given compound, you must determine first the intramolecular bond that exists between atoms of compounds. Chemical Formula and Chemical Name Once again, chemical formula is the shorthand of expressing the types and the number of atoms in a substance. The way of writing the chemical formula and chemical name of ionic compound is different from the covalent compound. a. Ionic Compound In writing the chemical formula of an ionic compound, do the following steps below. We will use sodium chloride as an example of a chemical name that need to be converted into chemical formula. Step 1 (Atoms involved) - Sodium and Chlorine 6 www.shsph.blogspot.com Step 2 (Chemical symbol) - Na + Cl Step 3 (Formed Ion) - Na+1 + Cl-1 The Na has a charged of +1 because it tends to give 1 valence electron to chlorine atom to become stable. Most metal atoms whose valence electrons are ranging from 1-3, they tend to give valence electron to become stable thus becomes positive ion known as Cation. Since Na has 1 valence electron, it will give its valence electron to chlorine forming sodium ion. While Cl has a charged of -1 because it tends to accept 1 valence electron from sodium atom to become stable. Most nonmetal atoms whose valence electrons are ranging from 5-7, they tend to accept valence electron to become stable thus becomes negative ion known as Anion. Since Cl has 7 valence electrons, it needs 1 valence electron from Na, it will accept 1 valence electron from sodium forming chlorine ion. Step 4 (Criss-cross multiply the charges) - Na+1 + Cl-1 1 1 Step 5 (Remove the plus sign to determine the chemical formula) - Na 1 Cl 1 or NaCl (note the charges become subscript) If you want to reverse the process, let us say naming an ionic compound, do the following steps below. We will use NaCl as an example of a chemical formula that need to convert to chemical name. Step 1 (Chemical name involved) - Sodium and Chlorine Step 2 (Change the last 4, 3 or 2 Letters of the name of nonmetal element into -ide) - Sodium and Chloride Step 3 (Remove the word and then combined the two words) - Sodium chloride b. Covalent Compound In writing the chemical formula of an covalent compound, do the following steps below. We will use Carbon tetrachloride as an example of a chemical name that need to be converted into chemical formula. Step 1 (Atoms involved) - Carbon and Chlorine Step 2 (Chemical symbol) - C + Cl Step 3 (Number of atoms)) - 1 + 4 Note that the carbon has 1 atom while chlorine has 4 atoms. We can determine the number of atom based from the Greek prefixes used before each type of atom. In Carbon tetrachloride, there is no Greek prefix written before the word carbon. This means that the number of carbon is 1. In Greek prefix, 1 is mono but there is no prefix mono before the word carbon. This is because the prefix mono is 7 www.shsph.blogspot.com not allowed to be written at the beginning of the chemical name. From supposedly Monocarbon tetrachloride, it is name as carbon tetrachloride. Greek Prefixes 1- Mono 4- Tetra 7-Hepta 10- Deca 2- Di 5- Penta 8- Octa 3- Tri 6- Hexa 9- Nona Step 4 (Combined the chemical Symbol and number of atoms) - C 1 + Cl 4 Step 5 (Remove the plus sign to determine the chemical formula) - C 1 Cl 4 or CCl 4 If you want to reverse the process, let us say naming a covalent compound, do the following steps below. We will use CCl 4 as an example of a chemical formula that need to convert to chemical name. Step 1 (Chemical name involved) - Carbon and Chlorine Step 2(Determine the Greek prefix) - none and tetra Step 3 (Remove the word and then combined Greek prefix and Change the last 4, 3 or 2 Letters of the name of last nonmetal element into -ide) - Carbon tetrachloride HOLD ON AMIGO!!! Did you understand what you have read about chemical formula and chemical name of compounds? 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! 8 www.shsph.blogspot.com Mini-Performance Task (Collaboration) Activity 1 – FREEDOM WALL Procedure 1. Prepare manila paper, pentel pen, coloring materials and ruler 2. Given set of chemical names, choose 1 that you want to present before your teacher. You need to follow the steps below to solve the problem. Write your complete answers in a manila paper. You may add design that you want or remark as your expression of your feelings or experiences towards the solving process. 3. Post your output on the wall and explain it before your classmates. Output Presentation FORMAT FOR IONIC COMPOUND Step 1 (Atoms involved) - Step 2 (Chemical symbol) - Step 3 (Formed Ion) - Step 4 (Criss-cross multiply the charges) - Step 5 (Remove the plus sign to determine the chemical formula) - FORMAT FOR COVALENT COMPOUND Step 1 (Atoms involved) - Step 2 (Chemical symbol) - Step 3 (Number of atoms) - Step 4 (Combined the chemical Symbol and number of atoms) - Step 5 (Remove the plus sign to determine the chemical formula) - 9 www.shsph.blogspot.com SET OF COMPOUNDS Potassium fluoride Nitrogen dioxide Sodium bromide Sulfur dioxide Magnesium sulfide QUESTIONS 1. What is the chemical formula of the compound? 2. Is your chosen compound an ionic compound or covalent compound? What I Have Learned? (Critical Thinking) 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 and Chemical …. Name HOLD ON AMIGO!!! After you have filled-in the L component of the chart, proceed now to the what I can do. What I Can Do? (Character and Creativity) WORK IN PROGRESS Added task to you. Look for a product found at your home. Identify 1 chemical compound on its label then determine its equivalent chemical formula as well as uses. 10 www.shsph.blogspot.com HOLD ON AMIGO!!! Congratulations Mi Amigo! You are almost done in this lesson. Let us do the last part which is the assessment. Assessment (Critical Thinking) POST-TEST Problem Solving (10 pts.) IONIC COMPOUND – Calcium iodide Step 1 (Atoms involved) - Step 2 (Chemical symbol) - Step 3 (Formed Ion) - Step 4 (Criss-cross multiply the charges) - Step 5 (Remove the plus sign to determine the chemical formula) - HOLD ON AMIGO!!! Congratulations Mi Amigo!!! We are done in this module. You may now proceed to the next module. See you next time. 11 www.shsph.blogspot.com 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 Superintendent- Manila, Aida H. Rondilla- Chief Education Supervisor, Lucky S. Carpio- EPS and Lady Hannah C. Gillo, Librarian II- LRMS 12 www.shsph.blogspot.com ANSWER SHEET Module 6 - Writing and Naming the Chemical Formula of Compounds 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 given after you have completed this module. KWL CHART Topic Know Want to know Learned Chemical Formula and Chemical Name PRE-TEST 1. 3. 5. 7. 9. 2. 4. 6. 8. 10. POST-TEST Problem Solving (10 pts.) IONIC COMPOUND – Calcium iodide Step 1 Step 2 Step 3 Step 4 Step 5 13 www.shsph.blogspot.com Activity 1- Freedom Wall Output Presentation FORMAT FOR IONIC COMPOUND Step 1 (Atoms involved) - Step 2 (Chemical symbol) - Step 3 (Formed Ion) - Step 4 (Criss-cross multiply the charges) - Step 5 (Remove the plus sign) to determine the chemical formula) - FORMAT FOR COVALENT COMPOUND Step 1 (Atoms involved) - Step 2 (Chemical symbol) - Step 3 (Number of atoms) - Step 4 (Combined the chemical Symbol and number of atoms) - Step 5 (Remove the plus sign to determine the chemical formula) - Answer to Questions 1.________________________________________________________________________________ __________________________________________________________________________________ 2.________________________________________________________________________________ __________________________________________________________________________________ 14