Grade 9 Regular Science Week 7 Day 1 PDF

**SECOND QUARTER WEEK 7 DAY 1** I. **OBJECTIVES** A. B. **Learning Competency:** - II. **CONTENT: [ PERCENTAGE COMPOSITION]** III. **LEARNING RESOURCES** A. References 1. 2. B. Other Learning Resources **LESSON 10: Percentage Composition** IV. **PROCEDURE** A. **Reviewin...

**SECOND QUARTER WEEK 7 DAY 1** I. **OBJECTIVES** A. B. **Learning Competency:** - II. **CONTENT: [ PERCENTAGE COMPOSITION]** III. **LEARNING RESOURCES** A. References 1. 2. B. Other Learning Resources **LESSON 10: Percentage Composition** IV. **PROCEDURE** A. **Reviewing previous lesson or presenting the new lesson** B. **Establishing the purpose for the lesson** Green Cross Isopropyl Alcohol 500ml \| Alcohol, Green, Grocery The given pictures above show the amount of a certain substance in percentage. You are surrounded by percentages. The tag inside your t-shirt tells you what percentage of your t-shirt is made up of cotton. The nutrition facts on the side of a box of cereal tells you the daily percentage of nutrients per serving.  In chemistry, you can express the relative amounts of elements within a compound by calculating the **percentage composition.** C. **Presenting examples/instances of the new lesson** To understand the concept of percentage composition, study the information below. **Your mother went home bringing a fruit basket. The fruit basket contains 5 apples, 3 oranges and 7 mangoes.**  The table shows percentage of each fruit in the basket. ------------ ------------------------ ---------------- FRUITS TOTAL NUMBER OF FRUITS PERCENTAGE (%) A. Apples **5** **33.33 %** B. Oranges **3** **20.00%** C. Mangoes **7** **46.67%** ------------ ------------------------ ---------------- **\*\*\*To find the percentage of each kind of fruit in the basket, divide the number of fruits by the total number of fruits in the basket, then multiply it by 100%. Your answer should be expressed in two decimal places.** **SCIENCE 9 WEEK 7 DAY 2** D. **[PERCENTAGE COMPOSITION]** **Percentage Composition --** is the mass of each element in a compound divided by the total mass of a given compound, multiplied by 100%. **QUICK RECIPE:** **STEPS IN SOLVING PERCENTAGE COMPOSITION:** **Example \#1:** Potassium permanganate (KMnO~4~) is a versatile oxidant used to treat drinking water, wastewater, industrial process chemicals, plus numerous other applications. What is the percentage composition of potassium permanganate (KMnO~4~)? **STEP 1:** Calculate the Molar Mass of KMnO~4.~ 4x 16 = 64 1x 55 = 55 1x 39 = 39 TOTAL = 158 g/mol **STEP 2:** Divide the total atomic mass of elements of K, Mn and O by the formula/molar mass of the compound KMnO~4~. Then, multiply its quotient by 100%. 158 g 158 g 158 g **\*\*\*The mass percentage of all elements in a compound add up to 100%. In some cases, the sum of the mass percentages in a compound is not exactly 100%([99.99% or 100.01% are acceptable)] due to the rounding of values**. **Always express your answer in two decimal places.** E. **Example \#2:** Determine the percentage composition of ethanol **STEP 1:** 1x 1 = 1 1 x 16 = 16 5 x 1 = 5 2 x 12 = 24 TOTAL = 46 g/mol 46 g 46 g 46 g 46 g F. **[Percentage Composition of a Compound]** The mass of each element in a compound compared to the entire mass of the compound multiplied by 100 percent is called the percentage composition of the compound. Percent composition by mass refers to the percentage by mass of an element that exists in a compound. Percent composition by mass is an important concept in chemistry, because it helps us to understand and visualize the mass of atoms of elements in nature. Percent composition by mass is used in many applications relating to industry, pharmacy, and construction. The formula for percent composition by mass is written below: **SCIENCE 9 WEEK 7 DAY 3** G. Read the paragraph below carefully. **[Percentage Composition in Everyday Life]** Percentage composition plays an important role in everyday life. Percentage composition is used in jewelry to determine the correct percentage of a specific metal in an alloy (a mixture of metals). [Percent composition is also used to determine the correct amount of specific elements in a mixture of concrete, as well as to determine the correct amount of an element or mineral in specific pharmaceuticals. You can use the percentage composition to identify the nutritional values of the food products.] Furthermore, farmers use the concept of percentage composition in choosing the best fertilizer for their farming activities. H. - Percentage composition of a compound tells you the percentage by mass each element is made up in a compound. - Percent composition by mass is used in many applications relating to industry, pharmacy, and construction. **SCIENCE 9 WEEK 7 DAY 4** I. A. **Multiple Choice** Read each question carefully. Then, write your answer in **CAPITAL LETTERS.** \_\_\_\_\_1. Which of the following refers to the mass of each element in a compound divided by the total mass of a given compound, multiplied by 100%? \_\_\_\_\_2. How do you get the percentage composition of a compound? \_\_\_\_\_3. What is the percentage composition of each element in sodium sulfate (Na~2~SO~4~)? \_\_\_\_\_4. What is the percentage composition of nitrogen in sodium nitride (Na~3~N)? \_\_\_\_\_5. What is the percentage composition of oxygen in carbon monoxide (CO)? B. Calculate the percentage composition of the following compounds. Show your solution. 1. SiO~2~ 2. PbS 3. NaCl 4. Fe~2~O~3~ 5. C~12~H~22~O~11~ J. Soil that is already depleted of its nutrients needs fertilizer. One of the nutrients needed to replenish the soil is **Nitrogen**. Solve for the percentage composition of the element Nitrogen. a\. ammonium phosphate - (NH~4~)~3~ PO~4~ b\. ammonium sulfate - (NH~4~)~2~SO~4~ c\. ammonium nitrate - NH~4~NO~3~ d\. urea - CO(NH~2~)~2~ **QUESTIONS:** 1\. Nitrogen is the main component of all fertilizers. Which among the 3 fertilizers has the highest nitrogen content? 2\. If you are an agricultural technician helping a farmer, which among these fertilizers would you recommend? Why? **SCIENCE 9 WEEK 7 DAY 5** **MODULE IV SUMMATIVE TEST IN GRADE 9 SCIENCE** **Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Score: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_** **Grade and Section: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Subject Matter: [Science 9 Week 7]** **[SUMMATIVE TEST \# 4 ]** I. **MULTIPLE CHOICE** \_\_\_\_\_\_\_\_1. It refers to the total atomic mass of all the atoms in a formula unit. C. formula mass D. molar mass \_\_\_\_\_\_\_\_2. The constant number of atoms, molecules or formula units in a sample is known as; A. B. Avogadro's number C. Molar mass C. Mole D. Percentage composition \_\_\_\_\_\_\_\_3. It refers to the mass of each element in a compound, divided by the total mass of a given compound, multiplied by 100 %. A. B. C. C. Mole D. Percentage composition \_\_\_\_\_\_\_\_4. It is used to measure small amounts of atoms and molecules because they are too small to be weighed. C. Mole D. Percentage composition \_\_\_\_\_\_\_\_5. What is common to different substances having equal number of moles? They have equal\_\_\_\_ A. B. C. C. number of particles D. volume \_\_\_\_\_\_\_\_6. A mole refers to the amount of a substance that contains \_\_\_\_\_\_\_\_\_ particles. A. B. C. C. 602 x10^23^ D. None of the above \_\_\_\_\_\_\_\_7. How many moles of water (H~2~O) are there in 36 g of water? A. 1 mole C. 3 moles B. \_\_\_\_\_\_\_\_8. Carbonic acid has a formula of H~2~CO~3.~ The atomic mass of the component elements are: H = 1 g/mol, C = 12g/mol, O = 16g/mol. What is the molar mass of H~2~CO~3~? A. 10 g/mol C. 50 g/mol B. 42 g/mol D. 62g/mol \_\_\_\_\_\_\_\_9. Which quantity is represented by the symbol Ne? A. 1 gram of Neon C. 1 mole of Neon B. \_\_\_\_\_\_\_\_10. Which is the molar mass of potassium dichromate(K~2~Cr~2~O~7~)? K = 39; Cr = 52; O = 16 A. B. 255 g/mol C. 294 g/mol C. \_\_\_\_\_\_\_\_11. The molar mass of H~2~ gas is: A. 1 g/mol C. 3 g /mol B. 2 g/mol D. 4 g/mol \_\_\_\_\_\_\_\_12. The molar mass of 1 mole of acetylene (C~2~H~2~) is: A. 22 g/mol C. 26 g/mol B. \_\_\_\_\_\_\_\_13. Which of the following represents the molecular mass of ammonium sulfate (NH~4~)~2~SO~4~? N =14; H = 1; S = 32; O = 16 A. 63 amu C. 118 amu B. 66 amu D. 132 amu \_\_\_\_\_\_\_\_14. Calculate the mass of 0.25 moles of hydrochloric acid (HCl). Molar mass of HCl = 36 g/mol A. 5 g C. 9 g B. 7 g D. 36 g \_\_\_\_\_\_\_\_15. Find the mass in 1.25 moles of water (H~2~O). Molar mass of H~2~O = 18 g/mol A. 12.5 g C. 25.2 g B. 22.5 g D. 52.2 g \_\_\_\_\_\_\_\_16. Calculate the number of moles in 150 g of calcium carbonate (CaCO~3~). Molar mass of CaCO~3~ = 100 g/mol A. 1.5 moles C. 2.5 moles B. 2.0 moles D. 3.0 moles \_\_\_\_\_\_\_\_17. The percentage of carbon (C) in sucrose, (C~12~H~22~O~11~) is \_\_\_\_\_ A. 3.5 % C. 42.1 % B. 8.3 % D. 57.9 % \_\_\_\_\_\_\_\_18. Nitrogen is used as a main component of fertilizer, which of the following fertilizers has the highest percentage of nitrogen that you would recommend to be used by farmers? A. ammonium sulfate (NH~4~)~2~SO~4~ B. ammonium phosphate (NH~4~)~3~PO~4~, C. potassium nitrate KNO~3~, D. urea CO(NH~2~)~2,~ \_\_\_\_\_\_\_\_19. What is the percentage composition of carbon in glucose (C~6~H~12~O~6~)? A. 40.00% C. 60.00 % B. 50.00 % D. 70.00 % \_\_\_\_\_\_\_\_20. A ceramic tile cleaner is essentially made up of 130 g hydrochloric acid (HCl) and 750 g water, (H~2~O). What is the percentage mass of HCl? A. 5.00 % C. 12.0 % B. 7.50 % D. 14.8 % \_\_\_\_\_\_\_\_21. What is the % composition of aluminum (Al) in aluminum oxide (Al~2~O~3~)? A. 51% C. 53% B. 52% D. 54% \_\_\_\_\_\_\_\_22. Calculate the percentage composition of sodium (Na) in sodium carbonate, (Na~2~CO~3~). Molar mass of Na~2~CO~3~ = 106 g/mol A. 43.39% C. 43.41 % B. 43\. 40 % D. 4.42 % \_\_\_\_\_\_\_\_23-24. Chlorophyll (C~55~H~70~MgN~4~O~6~) is a dark green plant pigment. Chlorophyll has a molar mass of 906 g/mol. Calculate the percentage composition of Mg and N in chlorophyll. A. Mg = 2.65 %, N = 6.18% C. Mg = 2.77 %, N = 6.30% B. Mg = 2.75 %, N = 6.28% D. Mg = 2.80 %, N = 6.32% \_\_\_\_\_\_\_\_25. Calculate the percentage of magnesium (Mg) in magnesium sulfide (MgS), if the percentage of Sulfur is 57.14% A. 40\. 86 % C. 42.86 % B. 41.68 % D. 100 % II. Solve the given problems. Apply GUFSA in showing your solution. (5 points each) 1. 2.