Blast OFF Investigation

Review Factors that affect rate of reaction: Temperature: increased temperature = increased rate of reaction Increases speed of molecules and effectiveness of collisions Concentration: the more concentrated solution = increased reaction rate When molecules are packed into tight space they are more likely to collide!

Review Surface area: the amount of matter visible and available to react Increased surface area = increased rate of reaction Catalysts: a substance that increases the rate of a chemical reaction without being consumed by the reaction Provides an easier way for the reaction to occur Decreases the amount of collision energy that molecules need to break bonds and form new molecules

Blast Off! You will be given a film canister with a lid and chemicals that form a gas when mixed together (baking soda and vinegar) You will apply your knowledge of rates of reaction and the process of scientific design to blow the lid off of your canister in a specified number of seconds (5 seconds!) This lab will be completed in groups of 3 – 1 Lab Report must be handed in per group!!!

Materials: Baking soda Vinegar Scoopula Graduated cylinder Film canister Stop Watch Safety goggles

Blast OFF Question: How can a chemical reaction be controlled so that an event occurs at a specific time? Hypothesis: Whatever your group decides! Design: You will design an experiment to test variables that can affect build up of gas in the closed film canister. In your group you will discuss and decide on all the variables that may affect the time it would take for the lid to come off Have your design approved by the teacher

Blast OFF Observations: create a data chart with headings such as – Trails (#1,2,3), mL of baking soda, mL of vinegar, results, comments Apparatus: A diagram of your set up Method After design approval, put on goggles & collect materials Test design, analyze and decide on final recipe

Blast OFF Method (continued) Join the other groups (last 10 minutes of class) for the final “blast off” The winning team is those whose lid “blasts off” closest to the target time (5 seconds) Clean up – dispose of mixtures down sink with water and put away materials according to your teacher. Clean up your work station. Discussion questions: on handout provided

Mark Breakdown!