Surface area will increase the speed of reaction as the greater the surface of the solid reactants, the more particles are required to expose and ‘cover’ the capacity of the solid. Increased surface area results in an increased chance of collisions between reactant particles. Since the collisions become more frequent and abundant, the rate of reaction increases.
Aim
The aim of the experiment is to see if a greater surface area of a dissolvable tablet creates a faster or slower reaction
Independent Variable
The surface area of the tablet (halves, powdered and whole)
Dependent Variable
How fast the rate of reaction is to the surface area
Controlled Variables
The amount of water (250mL)
The type of dissolvable tablet
The overall weight of tablet
Hypothesis
The greater the surface area of a solid reactant the faster its rate of reaction
Materials
Beakers x 3
Aspirin Tablets
Mortar and Pestle
Stopwatch
Risk Analysis
This experiment is relatively safe, however apron and sturdy non-slip shoes should be worn
Method
1. Measure 250 mL into three beakers
2. Crush two tablets with mortar and pestle
3. Start the stopwatch when one full dissolvable tablet is dropped into the water
4. Stop the stopwatch when the water stops fizzing
5. Record Results
6. Repeat with half of a dissolvable tablet and record results
7. Repeat with a powdered tablet and record results
8. Repeat twice
Data Collection
Surface Area Trial 1 (sec) Trial 2 (sec) Average (sec)
Whole 77.4 79.2 78.3
Halved 64.6 66.0 65.3
Powdered 13.6 24.0 18.8
Diagram Data Processing
Discussion
From the data results, both trials are fairly similar and supply the same information. It shows that the whole tablet takes the longest to dissolve at an average of 78.3 seconds whilst halved tablets take an average of 65.3 seconds and powdered takes 18.8 seconds. This is because the increased surface area gives more particles to the reactant, creating
References: http://thehappyscientist.com/science-experiment/surface-area http://www.bbc.co.uk/schools/gcsebitesize/science/ocr_gateway_pre_2011/rocks_metals/7_faster_slower4.shtml http://education.technyou.edu.au/view/103/108/effect-surface-area Rate of Reaction on Surface Area and Temperature - www.chemicalforums.com/index.php?topic=59329.0