Factors Affecting Rate of a Reaction, Chemistry Design Lab

In reference to the collision theory, molecules act as small spheres that collide and bounce off each other, transferring energy among themselves when the collide. In order for a reaction to occur, there must be collisions between molecules. Through experimentation, factors are discovered that influence the reaction rates of chemical reactions include the concentration of reactants, temperature, surface area, the physical state of reactants, and a catalyst. This experiment regarding the factors that affect reaction rate tests the effects of increased concentration and

If the concentration of the solution is increased the particles have less room to move around which creates a greater chance of collisions. The surface area of the reactant greatly affects the speed of which it reacts because if the reactant is grinded up or cut up the solution has more room to get to it. The reaction rate can be calculated by the formulae; rate of reaction = total amount of reactant used or product made ÷ time taken. (Collision theory and rates of reaction, 2013)

There are three stages of the overall reaction. Reaction 1 is the rate determining reaction whereby iodide ions from Potassium Iodide (KI) are oxidised by Hydrogen Peroxide (H₂O₂) in an acidic solution. This reaction utilises the Hydrogen ion from Sulfuric acid (H₂SO₄) to form triiodide ions and water as products (B Z. Shackhashiri, 1992).

Many factors effect reaction rates, two shown above include temperature and concentration. Concentration affects the rate of reactions because the more concentrated a solution the more likely collisions between particles will be. This is simply because there are more particles present to collide with each other. When the temperature is higher, particles will

The rate of a chemical reaction often depends on reactant concentrations, temperature, and if there’s presence of a catalyst. The rate of reaction for this experiment can be determined by analyzing the amount of iodine (I2) formed. Two chemical reactions are useful to determining

If different amounts of enzyme solution are added to the hydrogen peroxide, then the highest amount of enzymes will have the greatest reaction rate because enzymes catalyze reactions, meaning more oxygen will be produced quicker.

Introduction: Chemical reactions are dependent upon two factors: temperature and concentrations of substance. We can monitor the rate at which a chemical decomposes or the rate at which a chemical substance appears. In this experiment we will be measuring the rate of decomposition of hydrogen dioxide with the following reaction:

This image explains that the higher the temperature, the concentration, and the pressure the faster the rate of the reaction is.

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.

Experimental strategy: The experimental approach that will be taken, in order to test my hypothesis involves the use of the spectrophotometer. This machine will enable me to examine the effect of different substrate concentrations on the rate of reaction (Bio 5LA- Lab # 5, pp.3). In brief, I will have to take varying concentrations of a substrate, add an enzyme to each of tubes filled with different concentrations, and rapidly place the tube into the spectrophotometer, in order to measure the time it takes the varying substances to change color. As a result, when the color change is visible in any of the varying substrate concentrations, it will be safe to say that, the enzyme has reacted with the substrate, to form an enzyme-substrate complex. Similarly, the time it took for a color change to happen, will allow me to observe and record the rate at which each reaction

The purpose of this lab is to further explore kinetics by measuring the rate of reaction of iodide ionwith peroxydisulfate ion: Reaction 1 (slow). The second purpose is to determine the amount offormed over a certain time interval, orby titrating thewith the thiosulfate reaction 2 (fast) which quickly turns theback to the iodide ion. The third purpose of this lab is to determine the period of the clock the time it takes for reaction 2 to turn blue and go to completion “end point” by the reaction of iodine and starch. The final purpose is to calculate the rate law and collect data at several temperatures to determine the activation energy of the

The presence of catalyst will cause hydrogen peroxide to break down into water and oxygen. The increase in the pH of the substrate will cause the increase in the rate of reaction. It will optimize at pH 7 and will diminish/moderate after pH 9.

Table 2 shows the concentrations of S2O8-2 and I- and the time of each reaction for each run. Rate of the reaction was calculated by dividing 1M with the time it took to complete the reaction. The constant k was calculated using the rate law (4), the x and y value was determined by the graphs below. Considering most of the k’s calculated by our laboratory class, the supposed real value of k must be 10/Ms for that reaction.

Kinetics of chemical reactions is how fast a reaction occurs and determining how the presence of reactants affects reaction rates. In this experiment the rate of reaction for Fe+3 and I- is determined. Because the rate of chemical reactions relates directly to concentration of reactants, the rate law is used to find the rate constant, and calculated with specified temperatures.

The stoichiometric equation for the reaction between iodine and acetone is below, followed by the rate equation (where x,y,z and k are the values to be obtained):