Collision Theory and Chemical Reaction Rate. physical science
- 1. WHAT IS COLLISION THEORY AND CHEMICAL REACTION RATE
- 2. Use simple collision theory to explain the effects of concentration, temperature, and particle size on the rate of reaction MELC 1
- 3. Chemical reactions have been a part of this world ever since everything began. From the 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 take place, although you may not recognize them. This is the reason we need to understand how chemical processes take place, be it naturally occurring or not.
- 4. Identify what kind of change occurs : Physical change or Chemical change.
- 5. Baking
- 7. Dissolving coffee in water
- 8. Dissolving sugar in water
- 9. Mixing a paint to make a new
- 10. All substances are composed 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: COLLISION THEORY
- 11. 1. Substances or particles of reactants must physically collide with enough energy 2. Substance or particles must come into contact or collide in the correct orientation (facing the correct way). COLLISION THEORY
- 12. The collision theory states that reacting substances must come into contact (collide) with enough activation energy, and in the correct orientation (facing the correct way), so that their electron shells can rearrange to form the products of the reaction. Therefore, any factor which changes the frequency or energy of the collisions will change the rate of the reaction. COLLISION THEORY
- 13. Video
- 15. 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.
- 16. Video
- 18. 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. ACTIVATION ENERGY
- 19. Temperature refers to how hot or cold a certain substance is. Usually, a rise in temperature of 10 0C 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. TEMPERATURE
- 20. The rate of a chemical reaction is affected by the concentration of reacting substances. The term concentration refers to the number of particles present in a given volume of solution. Concentration may also mean a measure of how much of the solute (something to be dissolved) is dissolved in a solvent (dissolving medium) to form a homogeneous mixture. So, a higher concentration means there is more of the solute in the solution. If the concentration of the reactant is increased, the rate of reaction also increases. When the number of particles of the reactant is increased, there is a great chance for particles to collide. CONCENTRATION
- 21. 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. SURFACE AREA AND PARTICLE SIZE
- 22. QUIZ TIME!
- 23. 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 Q uestion #1
- 24. Which of the following would NOT increase the rate of reaction? A. Increasing the temperature B. Adding catalyst C. Increasing the volume D. Increasing the concentrations Q uestion #2
- 25. Activation energy is the amount of energy required to? A. break the bonds between the reacting molecules B. make the reacting particles collide C. form the bonds between the product molecules D. convert the reactant to a single product Q uestion #3
- 26. The factor that would NOT affect the rate of chemical reaction. a. Concentration b. Humidity c. Particle Size d. Temperature Q uestion #4
- 27. The measure of the hotness and coldness of a substance. a. Energy b. Humidity c. Temperature d. Thermometer Q uestion #5