Physical Science Module 8, Study notes of Environmental science

Download Physical Science Module 8 and more Study notes Environmental science in PDF only on Docsity!

Physical Science

Quarter 1 – Module 8

Collision Theory and Chemical

Reaction Rate

Physical Science Alternative Delivery Mode Quarter 1 – Module 8: Collision Theory and Chemical Reaction Rate First Edition 2020 Republic Act 8293, Section 176 states that “no copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for exploitation of such work for profit. Such agency or office may, among other things, impose as a condition the payment of royalties.” Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this module are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Department of Education Secretary: Leonor Magtolis Briones Undersecretary: Diosdado M. San Antonio Printed in the Philippines by ________________________ Department of Education – RegionIV-A CALABARZON Office Address: Gate 2 Karangalan Village, Barangay San Isidro Cainta, Rizal 1800 Telefax: 02 - 8682 - 5773/8684-4914/8647- 7487 E-mail Address: [email protected]

ii

Introductory Message For the facilitator: Welcome to the Physical Science Grade 11 Alternative Delivery Mode (ADM) Module on Collision Theory and Chemical Reaction Rate! This module was collaboratively designed, developed and reviewed by educators both from public and private institutions to assist you, the teacher or facilitator in helping the learners meet the standards set by the K to 12 Curriculum while overcoming their personal, social, and economic constraints in schooling. This learning resource hopes to engage the learners into guided and independent learning activities at their own pace and time. Furthermore, this also aims to help learners acquire the needed 21st century skills while taking into consideration their needs and circumstances. In addition to the material in the main text, you will also see this box in the body of the module: As a facilitator you are expected to orient the learners on how to use this module. You also need to keep track of the learners' progress while allowing them to manage their own learning. Furthermore, you are expected to encourage and assist the learners as they do the tasks included in the module. Notes to the Teacher This contains helpful tips or strategies that will help you in guiding the learners.

iii

For the learner: Welcome to the Physical Science Grade 11 Alternative Delivery Mode (ADM) Module on Collision Theory and Chemical Reaction Rate! The hand is one of the most symbolized part of the human body. It is often used to depict skill, action and purpose. Through our hands we may learn, create and accomplish. Hence, the hand in this learning resource signifies that you as a learner is capable and empowered to successfully achieve the relevant competencies and skills at your own pace and time. Your academic success lies in your own hands! This module was designed to provide you with fun and meaningful opportunities for guided and independent learning at your own pace and time. You will be enabled to process the contents of the learning resource while being an active learner. This module has the following parts and corresponding icons: What I Need to Know This will give you an idea of the skills or competencies you are expected to learn in the module. What I Know This part includes an activity that aims to check what you already know about the lesson to take. If you get all the answers correct (100%), you may decide to skip this module. What’s In This is a brief drill or review to help you link the current lesson with the previous one. What’s New In^ this^ portion,^ the^ new^ lesson^ will^ be introduced to you in various ways such as a story, a song, a poem, a problem opener, an activity or a situation. What is It This section provides a brief discussion of the lesson. This aims to help you discover and understand new concepts and skills. What’s More This^ comprises^ activities^ for^ independent practice to solidify your understanding and skills of the topic. You may check the answers to the exercises using the Answer Key at the end of the module. What I Have Learned This^ includes^ questions^ or^ blank sentence/paragraph to be filled in to process what you learned from the lesson. What I Can Do This section provides an activity which will help you transfer your new knowledge or

What I Need to Know This module was designed and written with you in mind. It is here to help you master the use of simple collision theory to explain the effects of concentration, temperature and particle size on the rate of reaction. 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. But the order in which you read them can be changed to correspond with the textbook you are now using. The module is divided into two lessons, namely:

• Lesson 1 - Collision Theory
• Lesson 2 - Factors Affecting the Rate of Chemical Reactions After going through this module, you are expected to:

1. define collision theory and describe how it affects the chemical reaction; and
2. explain the different factors affecting the rate of reaction. What I Know Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper.
3. A chemical change that occurs when two or more substances combine to form a new substance. a. Activation Energy b. Chemical Kinetics c. Chemical Reaction d. Product
4. The measure of the change in the concentration of the reactants or products. a. Activation Energy b. Activation Rate c. Chemical Reaction d. Concentration

3. The substance or particles that enter into and is altered in the course of a chemical reaction. a. Catalyst b. Enzyme c. Product d. Reactant
4. The number of particles present in a given volume of solution. a. Catalyst b. Concentration c. Product d. Temperature
5. The measure of how fast or slow a reaction happens. a. Activation Energy b. Collision theory c. Particle Size d. Rate of Reaction
6. Condition that needs to be met for a chemical reaction to occur. a. Substance must be homogeneous. b. Temperature should be kept constant. c. Particles should maintain a certain distance to each other. d. Particles in the substance must collide and have enough energy.
7. The factor that would NOT affect the rate of chemical reaction. a. Concentration b. Humidity c. Particle Size d. Temperature
8. The factor that will slow down the rate of chemical reaction. a. Manual stirring of the substance. b. Placing substance in a hot water. c. Placing products in iced water. d. Placing reactants in ice bath.
9. The factor that does NOT show evidence of chemical reaction. a. Absorption of heat b. Change of color c. Change of size d. Liberation of heat
10. The measure of the hotness or coldness of a substance. a. Energy b. Humidity c. Temperature d. Thermometer

Lesson

Collision Theory

Chemical reactions have been a part of this world ever since everything began. From Big bang to the present day, everything happening around us has something to do with chemical reactions and chemical processes. Chemical reactions are common in our daily lives: from cooking, eating, cleaning to the different chemical processes like respiration, corrosion and fermentation. How our body lives and grows are results of many chemical reactions that takes place, although you may not recognize them. This is the reason we need to understand how chemical processes takes place, be it naturally occurring or not. This lesson will help enhance your understanding about how chemical reaction occurs and what are the different factors affecting chemical reaction. What’s In Recall Chemical or Physical Change? Directions: Identify what kind of change occurs by writing the word Physical change or Chemical change.

1. Baking a pie
2. Burning a paper
3. Dissolving coffee in hot water
4. Dissolving sugar in water

5. Mixing paint to make a new color What’s New Picture Analysis Directions: List down ideas you think of based on the given picture. Directions: Complete the sentence about reaction based on the given illustration. A reaction ______________________________________

   ---

   ---

   _________________________________________________. What is It The Collision Theory All substances are comprised of millions of tiny particles in constant motion. These particles are colliding with each other constantly in any substance. All collisions between particles do not result in a reaction. There are two factors that determine whether a reaction will occur between two particles that are colliding:
6. Substances or particles of reactants must physically collide with enough energy
7. Substance or particles must come into contact or collide in the correct orientation (facing the correct way).

_______________________________________________

_______________________________________________

_______________________________________________

_______________________________________________

As shown in figures 3 and 4, no reaction can take place between two particles if they are far apart. To form new bonds, atoms must come in contact with each other and have correct relative orientations so that the correct bonds are broken, atoms transfer to the correct positions (see also Figure 1). What is a Chemical Reaction? When two particles collide, sometimes a chemical reaction can occur, which means the bonds between two or more particles are broken and reformed, creating one or more new substances. The substances or particles that enter and is changed in the chemical reaction are called reactants and the substances that are formed are called products****. Let us look at the chemical reaction in photosynthesis: The reactants (left part of the equation) are carbon dioxide, water, and light while the products (right side of the equation) are sugar and oxygen. But for a chemical reaction to occur, several things must happen:

1. The particles must come into contact with one another or collide.
2. When the particles collide, the particles must be aligned correctly so that the right parts of the atoms or molecules are exposed. If they are not oriented correctly, no chemical reaction will take place.
3. The particles must collide with enough energy to break their chemical bonds. The amount of energy that must be available for a reaction to occur is often referred to as the activation energy. It is the measure of the change in the concentration of the reactants or products. The reaction rate of a chemical reaction is a measurement of the increase in the concentration of a product or the decrease in the concentration of a reactant as the reaction proceeds over time. Keep in mind that not all reactions occur at the same speed. Some are very slow while others are fast. The rate of reaction also depends on the type of molecules that are combining. If there are low concentrations of an essential element or compound, the reaction will be slower.

Factors Affecting the Rate of Reaction

1. Activation Energy The activation energy refers to the minimum energy required for a reaction to take place. When a collision provides energy equal to or greater than the activation energy, product can form. On the other hand, if the particles have energy that is less than the activation energy, the collision is not effective, and they just bounce off each other unchanged. The figure above shows a man trying to push a rock over the cliff. For the man to push the rock, he needs to have enough energy. If the man does not have enough energy, the rock will not move down the cliff. This energy needed for the man to push the rock over the cliff represents the activation energy. Can you think of another example to show how activation energy works?

---

---

---

2. Temperature Temperature refers to how hot or cold a certain substance is. Usually, a rise in temperature of 10 0 C doubles the reaction rate. The rate of a chemical reaction increases with increasing temperature. As the temperature increases, collision between atoms and molecules becomes faster resulting to build up of more energy. The increased kinetic energy will equal to or exceed the activation energy resulting to more collisions giving rise to a reaction. Let’s try to apply: Arrange the following samples according to the rate of solubility of sugar. (1 - fastest, 3-slowest) Cold water Hot water Tap water ________ ________ _________

4. Surface Area and Particle Size Surface area is the measure of how much exposed area a solid object has, expressed in square units. In a reaction between a solid and a liquid, the more finely divided a solid is, the faster is the rate of reaction. Likewise, as you powdered a solid, its surface area becomes greater, thus the particles have higher chance of colliding and faster reaction happens. To understand this further, try to analyze the picture and answer the questions below: How many reactant particles can be seen on Figure 1? __________________________ Which do you think is the solid particle on Figure 1? _____________________________ What have you observed to the reactant particles in Figure 2? ____________________

---

In which container will the solid particle dissolve faster and why?

---

---

**_What’s More_** 

Activity 1.1 Factors affecting Reaction Rates The rate at which reactants are consumed and products are formed during chemical reactions vary greatly. In this part of the module, you will discover how the different factors, such as concentration, temperature and particle size affect the rate of chemical reactions. The following video links are experiments that you will watch and observe before answering the “Activity Assessment.” A. Effects of concentration: https://www.youtube.com/watch?v=o_TJEHzjBLM B. Effects of Temperature: https://www.youtube.com/watch?v=izqJkdj1d4U Figure 1 Figure 2

C. Effects of Particle Size: https://www.youtube.com/watch?v=kQtKRBL3rJY Activity 1.2 Guide Questions Directions: Answer briefly and concisely the following questions. PART A: Effects of Concentration

1. What evidence shows that reaction occurs?

________________________________________________________________________

2 - 3. Compare the rate of formation of Hydrogen gas in a tube A containing diluted Hydrochloric acid (HCl) with that of tube B containing concentrated Hydrochloric acid (HCl).

---

---

4 - 5. Explain the effects of concentration on the rate of chemical reaction.

---

---

6. Show the correct chemical equation for the reaction of Magnesium (Mg) ribbon And Hydrochloric (HCl) acid. ______________________________________________________________________________ ______________________________________________________________________________ PART B: Effects of Temperature
7. In which temperature of Oxalic acid (C 2 H 2 O 4 ) and Sulfuric acid (H 2 SO 4 ) mixture that Potassium Permanganate (KMnO 4 ) dissolves faster? ______________________________________________________________________________ 8 - 9. What evidence shows that a fast reaction occurs?

   ---

   ---

10 - 11. How does temperature affect the rate of chemical reaction? ______________________________________________________________________________ ______________________________________________________________________________ PART C: Effects of Particle Size 12 - 13. Compare the speed reaction of powdered Calcium Carbonate (CaCO 3 ) with that of a lump of Calcium Carbonate placed in water? ______________________________________________________________________________ ______________________________________________________________________________ 14 - 15. How do particle size affect the rate of chemical reaction? ______________________________________________________________________________ ______________________________________________________________________________

What I Can Do Create your own 5 - minute experiment video by choosing one of the factors discussed in this lesson. Rubric for Grading The video will be scored from 1 to 5, with 5 being the highest. The criteria for grading are as follows: Criteria Expectations Visuals The video is clear and engaging. Camera shots tell the story visually and no lighting problems. Audio Loudness and dialogue are balanced. Spoken words show confidence and are convincing. Content Deliver of content is precise and complete. Emphasis given should be based on the discussion. Timeliness The video should consume the required 5 - minutes. For every less or added minute/s, points will be deducted.

Assessment PART A. MODIFIED TRUE OR FALSE Directions: Write the word TRUE if the statement is correct. If the statement is FALSE, change the italicized word to make the statement correct. _______________1. Decreasing the concentration of the reactants increases the collision frequency between reacting particles. _______________2. Increasing the concentration of a substance increases the kinetic energy of the particles that make up the substance. _______________3. Increasing the surface area of the reactant, increases the rate of the reaction. _______________4. Raising the temperature of the reaction increases the rate of the reaction by increasing the energy of the collisions between reacting particles. _______________5. If the reactant particles collide with less than the activation energy, the particles bounce back and no reaction will occur. PART B. IDENTIFICATION Directions: Identify what factor affects the rate of chemical reaction in the following situations. Use the choices below by writing the correct letter before the number. A. Temperature B. Concentrations C. Particle Size ________6. The food was refrigerated. ________7. A coal dust explosion happen in mines. ________8. Acid rain erodes marble fast. ________9. Two antacid tablets neutralizes acids faster than one tablet. ________10. Kindling is used to start a fire. PART C. MULTIPLE CHOICE Directions: Encircle the LETTER of the correct answer.

11. What conditions must be met in order for a chemical reaction to occur? A. Collision with proper orientation B. Sufficient activation energy C. Adding more reactant particles D. Both collision with proper orientation and sufficient energy