The consequence of molecular weight on the rate of diffusion was measured utilizing two trials viz. : the glass tubing trial and the agar-water trial. The set-up of the glass tubing trial used two cotton balls of the same size. One cotton ball is moistened with hydrochloric acid ( HCl ) and the other one is moistened with ammonium hydrated oxide ( NH4OH ) . The two cotton balls were inserted in both terminals of the glass tubing. NH4OH which has a lighter molecular weight ( 35. 0459 g/mole ) diffused with a faster rate ( dave=20. 25cm ) as compared to HCl which has a greater molecular weight ( 36. 4611g/mole ) and diffused with dave=16. 38 centimeter. A white ring of fume formed closer to the heavier substance. The agar-water gel set-up used a petri-dish of agar-water gel with three Wellss on it. A bead of K permanganate ( KMnO4 ) was put on one well. a bead of K bichromate ( K2Cr2O7 ) was put on the other and a bead of methylene blue was put on the 3rd good. Methylene blue which has the heaviest molecular weight of 374 g/mole occupied a little diameter of coloured country which is 11mm. and had the slowest rate of diffusion which is 0. 613 mm/min. Thus the lighter the molecular weight. the faster is the rate of diffusion.

Introduction
As we open a family ammonium hydroxide it will non take that long before the odor of it occupies the whole room. The gaseous molecules travel rapidly and blend with the molecules in the air which makes it possible for people to instantly smell the ammonium hydroxide every bit shortly as it is opened. Such procedure is known to be the diffusion ( Myers. Oldham and Tocci. 2006 ) . Gases tend to spread quickly with each other. It does non count even if the air in a peculiar topographic point is still because it will merely take some proceedingss before the ammonium hydroxide molecules occupy the topographic point. During the procedure of diffusion. the substance moves from an country of higher concentration to an country of lower concentration. Harmonizing to Myers. Oldham and Tocci ( 2006 ) . atoms of low mass diffuse faster than atoms of high mass. Harmonizing to Meyertholen ( 2007 ) . some other factors are considered to hold an consequence in increasing or diminishing the rate of diffusion. Such factors include temperature or presence of energy. the distance. the barriers. the concentrations and many more. At a certain temperature. the smaller atom diffuses faster than the bigger 1. This is because a bigger molecule requires greater force in able to travel such atom. unlike the smaller atom which simply needs a lesser force for it to travel ( Meyertholen. 2007 ) .

With this survey. we can deduce into a hypothesis that “the rate of diffusion of a atom is reciprocally relative to its size” . with that is the statement that “if molecular weight is involved in diffusion. so the substance with the lighter molecular weight will travel faster” . The glass tubing set-up was used to turn out that the molecular weight of a substance affects its rate of diffusion. Two cotton balls of the same size. one was moisten with hydrochloric acid ( HCl ) . other with ammonium hydrated oxide ( NH4OH ) . were plugged into both terminals of the glass tubing. NH4OH has a lower molecular weight of 35. 0459 g/mole while HCI has a molecular weight of ( 36. 4611 g/mole ) . Together they will organize ammonium chloride ( NH4Cl ) which will be the footing for mensurating which of the two travels/diffuses faster. In order to place the consequence of molecular weight to the rate of diffusion of different substances. the H2O agar-gel set-up was used.

Three Wellss are on the petri dish of agar-gel and three solutions are prepared. one bead of solution for every well. The solutions are potassium permanganate ( KMnO4 ) . K bichromate ( K2Cr2O7 ) . and methylene blue. Through mensurating the diameter of covered country of each solution for 30 proceedingss. rate of the diffusion were analyzed and compared. This survey aimed to find the consequence of molecular weight to the rate of diffusion of different substances via the glass tubing set-up and H2O agar-gel set-up. The specific aims were: 1. To place factors that affect the diffusion rate of substances. 2. To depict the effects of molecular weight and other factors like clip with rate of diffusion of the different solutions.

MATERIALS AND METHOD
Glass Tube Set-up
To mensurate the rate of diffusion through its molecular weight a glass tubing set-up was used. A glass tubing is placed into a fume goon. Two cotton balls of the same size was obtained. One cotton ball was soaked in hydrochloric acid ( HCl ) and the other was soaked in ammonium hydrated oxide ( NH4OH ) . Both cotton balls were plugged at the same clip on both terminals of the glass tubing. After some proceedingss. a white ring of fume was observed to organize near the hydrochloric acid ( HCl ) . The distance between the white ring of fume and the cotton ball with ammonium hydrated oxide ( NH4OH ) was recorded and the same was done with the distance between the white ring of fume and the cotton ball with hydrochloric acid ( HCl ) . Three other glass tube set-ups were obtained. measured and recorded. The entire distance of set-ups 1 to 4 were calculated by adding the distances of the two cotton balls from the white ring of fume. The ratio between the ( HCl ) and ( NH4OH ) was besides measured by spliting the ratio of each substance from its distance from the white ring of fume. Average distance was besides calculated by adding the entire distances of the four set-ups. The deliberate informations were organized into tabular array. Water Agar-Gel Set-up

To mensurate the rate of diffusion with the factors of molecular weight and clip the H2O agar-gel set-up was used. A petri dish with H2O agar-gel was set up. The water-agar gel has three Wellss on it. Three solutions with three different molecular weights were distributed to the three Wellss. The ruddy solution is the Potassium Permanganate ( MW 158 g/mole ) . the xanthous 1 is the Potassium bichromate ( MW 294 g/mole ) and the bluish solution is the Methylene blue ( MW 374 g/mole ) . After make fulling each well with a peculiar solution all of the same clip. the diameter of the coloured country for each well was measured and recorded for zero minute. For 30 proceedingss with a regular three-minute interval. the diameter of the coloured country for each well was measured. The records of all measuring were organized into tabular array. The mean rate of diffusion for each solution was obtained by calculating foremost the partial rate of diffusion at each interval. The expression for calculating the partial rate is … . Where… .

The partial rates were totaled and so divided to the entire figure of observations in order to acquire the norm of diffusion. The norm of diffusion of each solution is so graphed. The partial rates of distribution were besides put into graph for analysis and reading.

RESULTS AND DISCUSSIONS
Table1
The tabular array 1 shows the distance of HCl and NH4OH from the formed white ring of fume for each test. The white fume that was formed is really ammonium chloride ( NH4CI ) which is the merchandise between the reaction of gasses of both HCl and NH4OH. The four tests clearly showed the same form where the white ring of fume formed closer to HCI which has a heavier molecular weight. This observation merely reveals that NH4OH which has a lighter molecular weight diffused faster than HCl. The ring of smoke’s distance from NH4OH ranges from 19-22 centimeter while the ring of smoke’s distance from HCI ranges from16-17 centimeter. Calculating the mean distance of NH4OH-to-ring of fume and HCI-to-ring of fume made it clearer that NH4OH diffused with the faster rate of 20. 25 centimeter. Hydrochloric acid ( HCl ) has a molecular weight of 36. 4611g/mole and ammonium hydrated oxide ( NH4OH ) has a molecular weight of 35. 0459 g/mole. HCI is heavier in nature and a slower rate of diffusion is identified with it. NH4OH have the opposite state of affairs. The fact that the white ring of fume appeared loser to the HCI manifests that the NH4OH traveled faster and in longer distance as compared to HCI. Based on the information on table1. we could infer that the rate of diffusion of molecule comes in different measuring for different molecular weights.

Table 2
The table2 shows consequence of how fast Potassium permanganate. Potassium bichromate and methylene blue diffused after 30 proceedingss with the interval of three proceedingss per measuring. The rate of measuring was assessed by mensurating the diameter of the coloured country for each solution. Potassium permanganate with the lowest molecular weight ( 158 g/mole ) among the three covered the biggest diameter of coloured country. while Methylene blue with the highest molecular weight of 374 g/mole recorded to hold the smallest diameter of coloured country. The observation revealed that the greater molecular weight means a lower diameter of covered country. Table 3

Table 3 shows the tendency of rate of diffusion of each solution. In here Potassium bichromate ( has the 2nd lowest molecular weight ) and non Potassium permanganate ( has the lowest molecular weight ) appears to hold the fastest diffusion rate. With the said observation. the hypothesis that “the higher the molecular weight. the smaller the diffusion” appeared to be non ever right. That possibly because of the presence of some factors like the: A ) inaccurate measurings. B ) unequal sum of solutions put and C ) for non dropping the solutions all at the same clip. The consequences of the mean rate of diffusion are the footing of cognizing which of the three solutions diffused the fastest. Methylene blue ( has the greatest molecular weight ) systematically appears to hold the slowest diffusion rate. Figure 1

Purportedly a line that forms a missive “C” will be formed but the said image was failed to accomplish. Alternatively of the Potassium permanganate. the Potassium bichromate appears to hold the fastest diffusion rate of the three. The aforesaid factors possible created this sort of tendency. There are incompatibilities that are present. Figure 2

Figure 2 obviously showed Potassium permanganate diffused the fastest for the first proceedingss but as it approaches the 30-minute clip. the diffusion rate went slower and slower. But clearly it is still the Potassium permanganate that covered the biggest diameter among the three. Unlike the others. Potassium bichromate can be seen to hold a consistent diffusion rate. Methylene blue which has the greatest molecular weight of the three shows a tendency that is really inconsistent and really slow when it comes to the rate of diffusion. The hypothesis that “the lighter molecular weight. the faster the diffusion rate” is true for Methylene blue but non for the other two.

SUMMARYAND CONCLUSION
Two set-ups are used to prove the consequence of molecular weight and clip to the rate of diffusion. One is through the usage of Glass tubing set up where diffusion rate was measured through the distance of white ring of fume from hydrochloric acid ( HCl ) and ammonium hydrated oxide ( NH4OH ) . The other is through puting a bead three different solutions to three Wellss in a petri dish of H2O agar-gel. The solutions are Potassium permanganate. Potassium bichromate and Methylene blue. With the first set-up. NH4OH that has the smaller molecular weight of the two was measured to go faster than the HCI. NH4OH has an mean distance of 20. 25 as compared to HCI which has 16. 38. With the 2nd set-up. Methylene blue which has the biggest molecular weight appeared to hold the smallest mean rate of diffusion ( . 613 ) and smallest diameter of country covered.

This manifests that Methylene blue has the slowest rate of diffusion. Potassium bichromate appeared to hold a faster rate of diffusion ( . 776 ) when it is purportedly be the Potassium permanganate ( . 7476 ) . but so the two do non differ much from each other. The two set-up. though non one-hundred per centum. turn out that the smaller the molecular weight. the higher rate of diffusion. Unequal sum of solution for the three Wellss. uncoordinated manner of seting the solutions into the Wellss and some interior and outside factors played a large function in turn outing the hypothesis to be right. More accurate consequences will be produced if the experiment will be done with the absence of other factors that negatively affect the consequence.