5-1: Rates of Reaction

In this lab we tried to see how temperature, concentration, and surface area affect the rate of the reaction between vinegar and alka seltzer. In our experiment we first broke each of the alka seltzer tablets into 4 pieces. For the concentration procedure we first measured out 15 mL of waterand then and poured it in a film canister adding the quarter tablet to it. The cap was placed on tight, and we timed for how many seconds it took the cap to pop off. Then we continued the experiment by intensifying the concentration of vinegar, again recording the reaction time. The varibles held constant was the uncrushed 1/4 tablet. For the next two experiments the variable tested was the water temperature, and the surface area of the tablet. For the water temperature, we needed to keep the amount of water, and a non crushed tablet the same through all of the different trials because if we changed these things, or results would have been changed we would not know what had effect on what without a constant. Student B had the best method for this experiment because unlike the other two students, student B changed the temperature variables in order to get different outcomes. This is an important method because if you change the temperature, the rate of the cap on the container will either come off faster or slower depending upon the temperature it's at. If you varied mulitple variables at the same time you'd have multiple things going on and you wouldn't be able to figure out what caused a change due to the fact that other variables are changing too.

Each variable has changed the rate do to particle collisions due to effective collision. This means that the particles have collided in such a way that there will be a chemical reaction. The changes we made in the lab, influence the number of effective collisions that were occurring. This happens because each variable alters the effectiveness of the chemical reaction.Each particle changed the rate because as the temperature increased, the time it takes for the cap to come off was  faster. As the temperature decreases, the cap comes off at a slower rate. With the higher concentration of vinegar that is added with less alka seltzer the cap to comes off at a slower rate because the alka seltzer is what triggers the whole experiment. What I expected to happen did happen; I predicted that the higher the temperature, the faster the cap of the container would come off and the lower the temperature, the slower the cap of the container would come off.

Enrichment:
An example of a catalyst is the catalytic converter in a car. This is coated with platinum to reduce carbon monoxide emissions. Catalysts are used to speed up the rate of reaction it reduces the required activation energy needed for the reaction to occur.