Effect of molecular weight in the rate of diffusion

How does molecular weight affect the rate of diffusion

Figure 4 is a line graph showing this observed effect of time to the partial rate of diffusion of substances. The diameter of the colored area was measured in a tree-minute interval. Thus, the higher the molecular weight of a substance, the slower its rate of diffusion. It also diffuses the fastes and the highest average of diffusion as compared from the two other substances. A drop of each substance was then put into its assigned well at the same time, the petri dish was immediately covered afterwards. The measured diameter was recorded for zero minute. In conclusion, the molecular weight of a substance is inversely related to its rate of diffusion. The first phenomenon is effusion, which is the escape of gases through a tiny hole into an evacuated space. When passing by a bakery shop, we can directly smell the aroma of the bread and when going to a perfume store, we can soon smell the fragrance of the perfume. Hydrochloric acid has a molecular weight of Three wells in agar-water gel on a petri dish were placed by a drop of potassium permanganate KMnO4 , potassium dichromate K2Cr2O7 and methylene blue. Immediately, the two cotton balls were plugged simultaneously to both ends of the glass tube as shown in Figure 1. This results to their difference in some characteristics such as the rate of diffusion. Glass Tube Set-up School Science Lessons, After a white ring of smoke appeared inside the glass tube, the point where it was seen was marked.

In conclusion, the molecular weight of a substance is inversely related to its rate of diffusion. The tube test was initiated with the preparation of the set-up which was a two-feet glass tube placed horizontally to a pair of stand and locked with a clip. A two feet glass tube was horizontally clamped.

At a given temperature, a substance having lower molecular weight tends to move faster than a substance having higher molecular weight.

diffusion of potassium permanganate in agar

In the experiment, the solutions used were potassium permanganate KMnO4potassium dichromate K2Cr2O7 and methylene blue. The diameter of the colored area is measured at a regular three minute intervals for 30 minutes.

Molecular mass and diffusion

Thus, further experimentation is needed in order for the study to be validated. In the experiment, the solutions used were potassium permanganate KMnO4 , potassium dichromate K2Cr2O7 and methylene blue. That is, the point where the molecules of the two substances met and formed a solid product. The white ring of smoke, as said on the introduction of the study, is the result of the reaction between the NH4OH and HCl. Thus, the higher the molecular weight of a substance, the slower its rate of diffusion. The diameter of the colored area was measured in a tree-minute interval. The relationship of molecular weight of substances to its average rate of diffusion and relationship of time to the partial rates of diffusion of substances were presented through a graph as shown in Figures 3 and 4.

Two cotton plugs moistened with hydrochloric acid HCl and ammonium hydroxide NH4OH were simultaneously plugged in the tube. Based from the stated data above, the substance with the lowest molecular weight value diffused the fastest and the substance with the highest molecular weight value diffused the slowest.

Immediately, the two cotton balls were plugged simultaneously to both ends of the glass tube as shown in Figure 1.

What is the effect of temperature on diffusion rate

In conclusion, the molecular weight of a substance is inversely related to its rate of diffusion. Distance of the smoke ring formed by hydrochloric acid and ammonium hydroxide from each initial point on the glass tube. A drop of each substance was then put into its assigned well at the same time, the petri dish was immediately covered afterwards. The diameter in mm of the colored area was immediately measured and noted for zero minute, as shown in Fig. It can be inferred from Table 1 that the rates of diffusion of substances are inversely proportional to their corresponding molecular weights. In the experiment, the solutions used were potassium permanganate KMnO4 , potassium dichromate K2Cr2O7 and methylene blue. The average diffusion rates of the substances were plotted against their corresponding molecular weight. The partial rates of each substance were also plotted at time intervals. The larger the particle, the greater the force needed to move the particle. This shows that the reaction occurred near the HCl end of the tube. Diffusion is one of the properties observed in the study of gases, and it is generally a characteristic of all gases Metcalfe, Therefore, the rate of diffusion is relatively for substances with higher molecular weight. A table comparing the measurements of the distances was plotted and analyzed. Agar forms a gel with water, thus allowing for measurement of the movement of the particles. The distance from each initiation point of the cotton balls to the point where the smoke appeared was measured using a ruler.

Diffusion and Concentration Gradients. Silberberg states that given two gases at equal pressure, e. The larger the particle, the greater the force needed to move the particle.

how to calculate diffusion rate mm min

As illustrated in Figure 2, the size of the drops of potassium permanganate and potassium dichromate were comparatively bigger in contrast with methylene blue. That hypothesis can be tested using the agar-water gel setup.

Diffusion and molecular weight lab

It can be inferred from Table 1 that the rates of diffusion of substances are inversely proportional to their corresponding molecular weights. Generally, we can conclude that the average rate of diffusion is inversely proportional to the molecular weight of a substance. Computing for the partial rates and average rates of diffusion, potassium permanganate still had the highest average rate of diffusion 0. The ratio of the distance of each substance to the total distance was also computed as well as the ratio of one substance to the other and its average. Several factors may affect the rate of diffusion of substances. That is, as the time increases, the partial rate of diffusion of all the substances decreases. In the agar-water gel test, drops of potassium permanganate, potassium dichromate and methylene blue were simultaneously placed in separate wells in an agar plate. Rate of diffusion on solid, gas and liquids Experimentation on the diffusion was carried out in the fume hood.

Partial and average rates of diffusion of KMnO4, K2Cr2O7 and methylene blue on the agar plate at three-minute intervals.

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How does molecular weight affect the rate of diffusion?