The Effect Of Concentration On Rate Of Reaction With Sodium Thhiosulphate

Although unlike the change in concentration, when the temperature of the reactants were either increased or decreased their was no significant change. As shown in table 4. When the temperature was either increased or decreased to 10°C, 30°C, 40°C and 50°C the average times are all within one second of each other. Except for when the reactants were cooled to a further 5°C the reaction time was increased by more than double the reaction time. This showing that the results from the investigation did not fully support the stated hypothesis.

Title: The Effect Temperature of Sodium Thiosulfate Has On The Rate of Reaction with Hydrochloric Acid

When the concentrations were changed so did the rate of reaction. When the concentration was changed to 0.265M the rate of reaction dropped by a factor of 0.5 (50%) below the control value. Furthermore when 60mL of water was added to the bleach dropping the concentration too 0.132M the rate dropped by a factor of 0.7 (70%).

Question: How does changing enzyme concentration or temperature affect the reaction time of enzyme activity?

Hypothesis: If the concentration of the substrate is increased, then the rate of enzyme activity will decrease. This is because as the concentration of the substrate increases, there is an increasing amount of occupied active sites at any given moment. This will cause a decrease in the rate of enzyme activity as substrate-active site collisions are increasingly slowed down thus bringing down the rate of enzyme activity.

As the substrate in increased the initial reaction rate will increase until it is fully submerged and then will not increase any more. The relationship is linear. As the substrate concentration increases, the initial reaction rate increases.

The null hypothesis for the first experiment was that substrate concentration would have no effect on the reaction rate. It was hypothesized that the reaction rate would increase with rising substrate concentrations, until all active sites were bound. The null hypothesis for the second experiment was that temperature would not have an effect on reaction rates. It was hypothesized that until the enzyme is denatured, as temperature increased, so would the reaction rate.

In this experiment we tested the effects that enzymes and substrate have on chemical reaction rates, which is the rate at which chemical reactions occur.. This experiment tested how different concentrations of enzyme and substrate affected the light absorption measurements on a spectrophotometer. The experiment also tested how temperature affected the light absorption, and in a separate test, the effect of the enzyme inhibitor hydroxylamine was also tested. In the first test conducted, 3 different concentrations of enzyme, and three different concentrations of substrate were measured in a spectrophotometer. For the enzyme and the substrate, the measurements got higher as the concentrations were higher, but the over measurements of the substrate were smaller than those of the enzyme. In the second test conducted, the medium concentration enzyme was tested under the temperatures; 4°C, 23°C, 37°C, and 60°C. The measurements in this test got higher as the temperature got higher, but did the measurements under 4°C were overall significantly higher than the other temperature measurements. Lastly, the last test conducted showed that the measurements of the substance with 0 and 1 drop of hydroxylamine inhibitor went up, but the measurements of the enzyme with 5 drops of hydroxylamine inhibitor stayed rather low and did not change much. In conclusion, these experiments showed that chemical reaction rates are sped up with higher concentrations of enzyme, substrate,

2. Slope can be used to determine the effect of the magnesium on the reaction rate by how close it is to the number one, when it is showing an increase in reaction rate. As hypothesized, the magnesium with the greatest surface area would have the fastest reaction rate. Hence, it would have the greater slope value as well.

The two experiments investigated measure the activity of the enzyme, catechol oxidase. Specifically, they investigate the effect of decreasing amounts of enzyme on rate of reaction and effect of decreasing amounts of substrate on rate of reaction. Enzymes are proteins with specific structures determined by the sequence of amino acid used to accelerate and regulate biochemical processes; enzyme activity can be measured using the rate at which the reaction catalyzes and can be expressed in concentration of substrate or product. Catechol oxidase, the enzyme used in the experiments, can be found in potatoes and catalyzes the oxidation of catechol to ortho-quinone. This substance turns fruits brown when cut open. The ortho-quinone produced in the experiments was used to determine the reaction rate. The experiments involved enzyme dilutions mixed with water and catechol in experiment II and .026M catechol with water and potassium phosphate in experiment III. Both experiments were measured using a spectrophotometer. My hypothesis for experiment II stated that as the enzyme concentration increased the rate of reaction would also increase at a constant rate, and my hypothesis for experiment III stated that the substrate concentration would increase as the rate of reaction increased at a constant rate. The results concluded that in experiment II the enzyme concentration increased at a constant rate, while the reaction rate increased. The experiment III concluded that the

II. Problem: How does the amount of time given for an enzyme solution to catalyze affect the reaction rate of a substance?

After getting the results of the 5 different concentrations using the formula c=A/εl (Lambert-Beer Law). So a new graph was created using the concentration plotted versus the time (s). The final rates of the reactions for the five different trial were first trial was 0.5 mM/s , second trial 0.3 mM/s , third trial 0.05 mM/s , fourth trial 0.03 mM/s , and for the fifth was 0.005 mM/s. the final result of the curve line was not that accurate because of the trial 4th that was a little off.

This experiment supported the hypothesis that the stronger the concentration, the more efficient the enzyme catalysed chemical reactions. .As time continued, the amount of substrates that needed to be bind with an enzyme was reduced because most of the milk fats had been converted in to fatty acids, which then caused the rate of reaction to slow down as it was harder for the remaining substrates to collide with the enzyme. This means the moment where the reaction is the most effective is at the beginning, when the lipase solution was just added to the milk, which is known as the Initial Reaction Rate. This is reaction is displayed in graph 3, as all on the lines have a steep gradient at the begging of the test, which then begin to plateau towards the end of the reaction when the solution became colourless. It’s interesting that the 2% concentration had a higher initial reaction rate than the 4%

The data supports the hypothesis that an exponential relationship will be found between the change in temperature and the reaction rate, and that the highest temperature will have the fastest rate of reaction. The data also supports the hypothesis that as the concentration of Potassium Iodine increases so will the reaction rate, and vice versa for an increase in Sodium Thiosulphate concentration. The hypothesis that the Iron (II) ions will affect the reaction rate, and that the optimal amount will be about 0.1M of catalyst was partially supported.

Two catalyst reactants are used in the experiment, thiosulfate and starch, to dictate the time of reactions.