Chemistry gizmo (Best Graded) Latest Updated 2021

Vocabulary: activated complex, catalyst, chemical reaction, concentration, enzyme, half-life, molecule, product, reactant, surface area Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Suppose you added ...

Vocabulary: activated complex, catalyst, chemical reaction, concentration, enzyme, half-life, molecule, product, reactant, surface area Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Suppose you added a spoonful of sugar to hot water and another to ice-cold water. Which type of water will cause the sugar to dissolve more quickly? ___Hot_____ 2. Suppose you held a lighted match to a solid hunk of wood and another match to a pile of wood shavings. Which form of wood will catch fire more easily? ___Wood Shavings_____ Gizmo Warm-up A chemical reaction causes the chemical compositions of substances to change. Reactants are substances that enter into a reaction, and products are substances produced by the reaction. The Collision Theory Gizmo™ allows you to experiment with several factors that affect the rate at which reactants are transformed into products in a chemical reaction. You will need blue, green, and orange markers or colored pencils for the first part of this activity. 1. Look at the key at the bottom of the SIMULATION pane. In the space below, draw the two reactants and two products of this chemical reaction. Reactants: Reactant A has 2 vertical blue dots. Products: Reactant B has 2 vertical green dots with An orange dot in between them. 2. Click Play ( ). What do you see? __ ____I see Reactant A bouncing with and combining with Reactant B. _________________________________________________________________________ Product A has 2 vertical green dots. Product B has 2 vertical blue dots with an orange dot in the middle. This study source was downloaded by 100000796615030 from CourseHero.com on 09-03-2021 13:34:01 GMT -05:00 https://www.coursehero.com/file/33971230/Chemistry-gizmopdf/ This study resource was shared via CourseHero.com Activity continued from previous page) _________________________________________________________________________ Activity A: Temperature Get the Gizmo ready: • Click Reset ( ). • Check that the Reactant concentration is set to 1.0 mol/L, the Catalyst concentration is set to 0.00 mol/L, and the Surface area is Minimum. Question: How does temperature affect the rate of a chemical reaction? 1. Observe: Select the ANIMATION tab. View the animation with No catalyst selected. What do you see? __________All of Reactant B is in a group to the far right. Reactant A is spread throughout the platform. It isn’t touching Reactant B, though.______ When two reactant molecules meet, they form a temporary structure called an activated complex. The activated complex breaks up into the product molecules. 2. Observe: Return to the CONTROLS pane. Set the Temperature to 0 °C and the Simulation speed to its maximum setting. Click Play. A. Describe the motions of the molecules. ______Reactant A is moving fast. Some of Reactant B is breaking off to form Product A and Product B._____ B. Now set the Temperature to 200 °C. How does increasing the temperature affect the motions of the molecules? ____ The molecules are moving faster._________.__ What do you notice about the chemical reaction at the higher temperature? _______ The chemical reaction occurs faster than lower temperature.______ 3. Interpret: Select the GRAPH tab. Click the zoom out button (–) until you can see the whole graph. What does this graph show? __It shows the amount of products and reactants throughout the process.______ 4. Predict: How do you think temperature will affect the rate of a chemical reaction? ________ _I believe the temperature will make the chemical reaction occur faster or slower depending on how hot or cold it is.______ (Activity A continued on next page) A. ( This study source was downloaded by 100000796615030 from CourseHero.com on 09-03-2021 13:34:01 GMT -05:00 https://www.coursehero.com/file/33971230/Chemistry-gizmopdf/ This study resource was shared via CourseHero.com Activity continued from previous page) _________________________________________________________________________ 5. Gather data: Click Reset. A useful way to compare reaction rates is to record the time required for half of the reactants to react, called the half-life of the reaction. With the Temperature set to 200 °C, click Play. Click Pause ( ) when the number of reactant molecules is 10. Record the half-life time in the first space of the table below. Trial 200 °C 150 °C 100 °C 50 °C 1 9:32 8:46 15:04 40:12 2 12:58 7:16 14:26 91:28 Mean half-life 11:15 8:01 14:45 1:5:50 Repeat the experiment at different temperatures to complete the table. (Note: To get exact times, you can refer to the TABLE tab.) 6. Calculate: Calculate the mean half-life for each temperature. Fill in these values above. (Hint: To get an exact mean, first convert each time to seconds by multiplying the minutes value by 60 and adding this to the seconds. To find the mean in seconds, add up the two times and divide by two. Convert the answer back to minutes and seconds.) 7. Analyze: What do your results indicate? _____The higher temperatures make the molecules react faster._______ 8. Draw conclusions: For two molecules to react, they must collide at just the right angle and with enough energy to break the original bonds and form new ones. Based on these facts, why does the reaction tend to go more quickly at higher temperatures? _____With higher temperatures, the molecules move faster, so it have more chances to hit each other. ______ 9. Apply: Paper must be heated to 234 °C to begin reacting with oxygen. This can be done by putting the paper over a flame. Why do you think the paper must be heated to start burning? ________It needed energy to start the chemical reaction.____ This study source was downloaded by 100000796615030 from CourseHero.com on 09-03-2021 13:34:01 GMT -05:00 https://www.coursehero.com/file/33971230/Chemistry-gizmopdf/ This study resource was shared via CourseHero.com _________________________________________________________________________ Activity B: Surface area and concentration Get the Gizmo ready: • Click Reset. • Check that the Catalyst concentration is set to 0.00 mol/L and the Surface area is Minimum. • Set the Temperature to 200 °C. Introduction: Reaction rates are also influenced by surface area and concentration. The surface area of a solid is a measure of how much of the solid is exposed to other substances. The concentration of a substance is a measure of how many molecules of that substance are present in a given volume. Question: How do surface area and concentration affect reaction rates? 1. Observe: Change the Surface area from Minimum to Maximum. You can imagine that a solid reactant has been dissolved in a liquid. How does this change how many Reactant B molecules are exposed to Reactant A? ______Reactant B is separated from each other.________________________ 2. Predict: How do you think increasing the surface area will affect the rate of the reaction? _______I feel the reaction will occur faster.____________ 3. Gather data: Set the Reactant concentration to 2.0 mol/L. Use the Gizmo to measure the half-life of the reaction for each surface area setting. (There will now be 20 reactant molecules left at the half-life.) Then, calculate the mean half-life for each setting. Trial Minimum surface area Maximum surface area 1 5:28 0:56 2 5:32 0:58 Mean half-life 5:30 0:57 4. Analyze: What do your results indicate? ______The minimum surface area takes longer for molecules to react half way.______ 5. Explain: Why does the reaction proceed more quickly when the surface area is increased?