The Effect of Varying Molecular Weights on the Rate of Diffusion
The Effect of Varying Molecular Weights on the Rate of Diffusion of Substances
August 22,2012
ABSTRACT
The effect of molecular weight on the rate of diffusion was verified by the 2 tests: the glass tube setup and the water agar-gel setup. In the glass tube setup, two cotton balls were soaked in the solutions of hydrochloric acid (HCl) and ammonium hydroxide (NH4OH) and were simultaneously placed on both ends of the tubing.NH4OH had a lighter molecular weight of 35 g/mole which diffused at a faster rate of 24.8 cm and formed a white smoke near the HCl end that had the molecular weight of 36 g/mole. The water agar-gel setup was made up of a petri dish containing the gel with three wells. Drops of potassium permanganate
(KMnO4), potassium dichromate(K2Cr2O7) and methylene
Blue were concurrently placed in the wells. Methylene
Blue had the smallest diameter which diffused at the slowest
Rate of 0.13 mm/min since it has the largest molecular
Weight. Thus, the larger the molecular weight, the slower
It will diffuse.
INTRODUCTION
The particles in different substances are never still because of its capability to keep moving and bumping into each other all the time. This type of movement is called diffusion (Kent, 2000). Diffusion is the process by which substances spread from regions of high concentration to the regions of low concentration until there is equilibrium.
According to Rowland (1992), the greater the difference in concentration is then the faster the rate of diffusion of the substance. This may then serve as one of the factors that affect the rate of diffusion. Some factors include the temperature, polarity of the molecules and its molecular weight. Molecular weight could then be defined as the mass of a molecule that is relative to the mass of atom. Satake (1997) also proposed that molecular weight is proportional to the rate of diffusion. Through this study, it will be determined whether Satake’s proposal is true or not.
Based on
August 22,2012
ABSTRACT
The effect of molecular weight on the rate of diffusion was verified by the 2 tests: the glass tube setup and the water agar-gel setup. In the glass tube setup, two cotton balls were soaked in the solutions of hydrochloric acid (HCl) and ammonium hydroxide (NH4OH) and were simultaneously placed on both ends of the tubing.NH4OH had a lighter molecular weight of 35 g/mole which diffused at a faster rate of 24.8 cm and formed a white smoke near the HCl end that had the molecular weight of 36 g/mole. The water agar-gel setup was made up of a petri dish containing the gel with three wells. Drops of potassium permanganate
(KMnO4), potassium dichromate(K2Cr2O7) and methylene
Blue were concurrently placed in the wells. Methylene
Blue had the smallest diameter which diffused at the slowest
Rate of 0.13 mm/min since it has the largest molecular
Weight. Thus, the larger the molecular weight, the slower
It will diffuse.
INTRODUCTION
The particles in different substances are never still because of its capability to keep moving and bumping into each other all the time. This type of movement is called diffusion (Kent, 2000). Diffusion is the process by which substances spread from regions of high concentration to the regions of low concentration until there is equilibrium.
According to Rowland (1992), the greater the difference in concentration is then the faster the rate of diffusion of the substance. This may then serve as one of the factors that affect the rate of diffusion. Some factors include the temperature, polarity of the molecules and its molecular weight. Molecular weight could then be defined as the mass of a molecule that is relative to the mass of atom. Satake (1997) also proposed that molecular weight is proportional to the rate of diffusion. Through this study, it will be determined whether Satake’s proposal is true or not.
Based on