The results do not support the hypothesis that a higher surface area to volume ratio would result in sulphuric acid being diffused into the agar cubes in the shortest amount of time. This is evident in the results as the exact opposite to what was predicted occurred. Instead of the smallest cube with the largest surface area to volume ratio of 1cm3 having the quickest diffusion rate, it conversely took the longest at 0.092 cm3 per second, whilst the 2cm3 cube with 0.0384 cm3 per second took the least amount of time. This directly refutes the hypothesis. There was also no consistent trend evident in the results. Between the two largest blocks of 2cm3 and 3cm3, there was only a 0.00243 cm3 per second, however, and in contrast to the hypothesis, …show more content…
The temperature of the sulphuric acid was not measured throughout the experiment, however the room in which the experiment was conducted was kept constant, so the chance of any large error due to unknown temperature of the sulphuric acid was most likely reduced. The amount of sulphuric acid used was also controlled by measuring 100mL with a 100mL measuring cylinder to ensure that the results would be consistent. The volume of the agar cubes was calculated from the surface area of each agar cube, both before and after they had been in the sulphuric acid. This increased the reliability of the results as it allowed the rate of diffusion of the sulphuric acid into the agar cubes to be calculated more accurately. The concentration of the acid was 0.1M, which was placed in all three agar cubes to maintain consistency of results. Another variable of the experiment that was controlled was the time in which the agar cubes spent in the sulphuric acid. The time allowed calculation of the rate of diffusion. The size of the agar cubes was controlled by using a grid and scalpel to, as accurately as possible, cut the agar cubes into the appropriate sizes. The shape of the agar cubes was also controlled. In future, this could be experimented with to investigate how different shaped agar blocks affect surface area to volume ratio and hence the rate of …show more content…
A larger sample size could have enabled averages to be resulted, and the experiment could have had several trials until concordant results are attained to increase the reliability. To enhance the accuracy of the results, a machine such as a cheese wire to cut straight along the edge could have been employed that would more accurately cut the cubes and hence reducing human error. This would be efficient as there is a large chance of human error when cutting the cubes by hand as the agar is slippery. Cubes with different sizes could be observed to improve the validity of the experiment. The weight of the bottom of the cubes pushing against the beaker likely caused an error to occur. This could have impact different sized cubes to varying extents. Human error also occurred when the 3cm3 cube had to be repeated as it was initially incorrectly measured. This could have contributed to the results being less reliable as the concentration of phenolphthalein in the agar cube could have been different from that of the other cubes (Unknown, 2008). The method was quite successful and produced relatively accurate results. Next time, a substance such as hydrochloric acid could be used instead of sulphuric
As we shook the first cube for 3 minutes, the mass decreased from 2.35g to 1.42g. During test 2, we shook and received a 1.64g, after the starting total of 4.7g. For the final mass we got 1.99g, a total of 5.06g grams turned into sugar dust. Our graph was almost a straight line. On trial 1, i believe we didn 't shake it as hard as we did of
Everyday Use and Sula are coming of age stories. They both illustrate times in people’s lives when they have to decide to how they are going to live with their past and themselves. The short story "Everyday Use", Alice Walker emphasizes the aspect of individuality. The story focuses on the lives of two sisters, Maggie and Dee.
Additionally, it was difficult obtaining a piece of rhubarb that was thin and particularly red, therefore the effect could not be best observed in the cells. Part B: Design your own experiment Parts of this practical were taken and slightly altered from the following link http://www.markedbyteachers.com/gcse/science/investigate-the-effect-of-surface-area-on-osmosis-in-potato-tissue.html Aim: To observe the effect different surface area: volume ratios have on osmosis in potato tissue. Hypothesis: If the potato has a larger surface area: volume ratio, the quicker osmosis will take place and the larger the mass will be at the end of the experiment, therefore the difference in mass of the potatoes from the start of the experiment to the end of the experiment will be larger. Additionally, the potato pieces left in a saltwater solution will decrease in mass, whereas the pieces left in water will increase in mass.
Results: Table 1: Results from the Salicylic acid (g) and the Purity of ASA (g) Experiment Mass of salicylic acid (g) 0.14 g Mass of filter paper (g) 0.47 g Mass of “impure” ASA + filter paper (g) 0.56 g Mass of prepared “impure” ASA (g)
For this lab I will be using water and sucrose to demonstrate the rate of osmosis. In this lab I will be exploring how temperature impacts the rate of osmosis by placing pieces of potato of equal size in solutions of different temperatures and observing the change in mass of potato after a given period of time. The change in mass will indicate the rate of osmosis.
Materials: The materials that I will be utilizing during these experimentations are three to four ice cubes, one cup for measuring, six unblemished cups, one stopwatch, one hot water source, three tablets of Alka-Seltzer, one thermometer that measures from negative
The control in the experiment is water. Units used while timing the productivity of gas from an Alka-Seltzer tablet in different temperatures is, seconds. In order to find out if temperature controls the rate of chemical reaction, whether hot water is a more effective way to make the gas produce at a faster speed, it would be necessary to compare the results of different temperatures at the end of each trial. In order to do this the scientists will measure the volume of gas that is produced within a 10 second interval time after the tablet begins to react.
Firstly, because the NaHCO3 compound was not stored in a sealed container, therefore dust particles could have changed the results, and making the product impure. Also, there are uncertainties associated with the instruments used in this experiment. This, if the products were measured slightly more than should be, this could have affected the concentrations of the solutions, and therefore causing a larger
We then took the potato cores out of the empty beaker and dabbed them lightly with paper towel to get any excess solution off. We did this quickly and following it we then took the mass of all four potato cores again and recorded
In this practical agar jelly cubes will be used to represent a cell. AIM: To model diffusion in a practical form and investigate the effect of surface area to volume ratio. HYPOTHESIS: It is hypothesised the smaller the cube the quicker and bigger the rate of diffusion will be and with a larger cube there will be a smaller percentage of diffusion due to its bigger volume.
Uncontrolled Environmental conditions Atmospheric conditions The controlled variable Concentration of amylase was kept under control by measuring the amount of amylase used and also it was made sure the percentage of amylase used was 1%. The Amount of amylase/starch used were kept to 5cm3 at all times. Materials needed Beakers Bunsen burner Test tube Thermometer Stopwatch Test plate Glass rod Starch Amylase solution Water bath Iodine solution. Test tube holder Labels Marker Procedure First 5 test tubes were taken and labeled with numbers from 1 to
Also, although this likely served no contribution in disheveling the results, using a stirrer of the same material to ensure the separate testing of each substance will be as uniform as
Chemistry IA Background information: Introduction: Electrolysis it’s a chemical process that when you pass an electric current into a solution or a liquid that contains ions to separate substances back to their original form. The main components that are required for electrolysis to take a place are: Electrolyte: it’s a substance that when dissolved in water it ionize and then it will contain free moving ions and without these moving ions the process of electrolysis won’t take place. Direct current (DC): This current provides the energy needed to discharge the ions in the electrolyte Electrodes: it’s an object that conducts electricity and it’s used in electrolysis as a bridge between the solution and power supply. A great example
Introduction The goal of the experiment is to examine how the rate of reaction between Hydrochloric acid and Sodium thiosulphate is affected by altering the concentrations. The concentration of Sodium thiosulfate will be altered by adding deionised water and decreasing the amount of Sodium thiosulphate. Once the Sodium thiosulphate has been tested several times. The effect of concentration on the rate of reaction can be examined in this experiment.
That caused a new initial reading of NaOH on the burette (see Table1 & 2). The drops were caused because the burette was not tightened enough at the bottom to avoid it from being hard to release the basic solution for titrating the acid. The volume of the acid used for each titration was 25ml. The volume of the solution was then calculated by subtracting the initial volume from the final volume. We then calculated the average volume at each temperature.