College of Science and Mathematics
Department of Biological Sciences
In partial fulfillment of :
BIOLOGY 101.1
(Scientific Paper on Diffusion)
Submitted by :
Diate, Kim P. (B.S.E Gen.Sci.1)
Submitted to :
Olive S. Anies, Ph.D
ABSTRACT
This scientific paper investigates my hypothesis that "Higher molecular weight produce faster diffusion". Diffusion is a process of equalization which involves movement of molecules from an area of high concentration to an area of low concentration (Biology 101.1). As Thomas Graham (1831-1833) found out on his study that gases of different nature diffuse with each other, it is a challenge as to how true it is to solids.
The effect of molecular weight on the rate of diffusion was assessed using Methylene Blue (320 g/mol) and Potassium Permanganate (158 g/mol). This subjects have varying molecular weight, one higher than the other. It is important to note whatvis Molecular Weight. MW is the sum of the mass of each constituent atom multiplied by the number of atoms that element in the molecular formula. With the aid of agar plates, we put some substrate on it for purpose of observation. Having a time-interval of 15 minutes, we gathered the data for interpretation. As it all went out, Potassium Permanganate having a lesser molecular weight diffuse faster than Methylene Blue. At first rate (Methylene Blue=0.07 mm/min.) while (Potassium Permanganate= 0.27 mm/min.) The result was synonymous with the other groups. Then it leads me to abandon my first hypothesis and formulate a new one that states: "Molecular Weight is inversely proportional to the rate of diffusion; Higher MW means slower diffusion.
However, According to Meyertholem (2007), there are still other factors aside from MW that affects the rate of diffusion. These are 1.)Temperature (higher temperature: faster diffusion), 2.) Concentration difference
References: Metillo, E.B., et.al, Biology 1, MSU-Iligan Institute of Technology, 2012 Silberberg, Principles of General Chemistry, McGraw International Edition