Rate of Reaction

December 17, 2003

Rate of Reaction-Report

The purpose of this lab was to find the rate of reaction. I watched to see how fast Alka-Seltzer would react with different liquids. I changed the type of liquid from water to vinegar for some of the experiments. I also used one tablet that was solid and one that I had crushed up to see the differences. I changed the temperature with each new experiment, except when I was comparing and contrasting solid to ground up tablets. I always used the same amount of liquid also. The tablet that was ground up always dissolved quicker than the solid tablet in the same temperature. This is because of molecular collisions. The solid tablet could only make contact with the liquid on the surface, causing the reaction to always occur from the outside to the inside, which made the reaction take longer. The ground up tablet could make contact with the liquid all through the powder, causing more molecular collisions in the same amount of time. I also noticed the hotter the liquid was the faster the reaction time was. This is because there is more energy in the water and the molecules are colliding faster causing the reaction to speed up. From my results I predicted that a solid tablet, in water, would react in 73.9 seconds at 13°C. I also predicted that a ground up tablet would react in 43.3 seconds at 13°C. I made my predictions by looking at the average reaction time from my labs, and calculating the average reaction speed. The solid tablets reaction speed was about 3.61 seconds per degree. While the ground up tablets reaction speed was about 1.67 seconds per degree. After I found the speed of the reaction, I multiplied the average reaction speed by the temperature I was trying to predict. In my results both the solid and the ground up tablets dissolved faster in water than in vinegar. I personally thought that the tablets would actually dissolve faster in vinegar.Type of Liquid Amount of Liquid(mL) Temperature of Liquid (°C) Consistency of Tablet Time of Reaction (Seconds)

Water 250 mL Cold(4°C) Solid 110 Sec.

Water 250 mL Cold(4°C) Ground Up 60 Sec.

Water 250 mL Room(21°C) Solid 45 Sec.

Water 250 mL Room(21°C) Ground Up 30 Sec.

Water 250 mL Hot(43°C) Solid 25 Sec.

Water 250 mL Hot(43°C) Ground Up 20 Sec.

Vinegar 250 mL Room(21°C) Solid 90 Sec.

Vinegar 250 mL Room(21°C) Ground Up 75 Sec.

Rate of Reaction-Data Table