I facilitated the design of the experiment by asking my students a series of questions that were meant to feel like it was a genuine conversation happening between scientists interested in answering a question.
The method used for the experiment I have just carried out is reliable and did show the relationship between concentration and rate of reaction even though there was a slight margin of error because when turning the cylinder upside down a small volume of water is lost, if this problem could be solved along with the surface area it would improve the accuracy further.
There are a number of variables that can affect the rate of my experiment i. I am going to measure how long it takes a piece of magnesium no more than 20m in length to react in different concentrations of acid The lab itself took about 30 mins to do but because I involved them in the experimental setup and dedicated time to construct arguments that were presented, debated, and refined, the entire process took 3 periods 1 hr each.
If you double the concentration of a reactant, the rate of reaction doubles. The timer starts after this initial swirl.To find additional trends I could time the experiment for longer as over time there may be new patterns formed because the reaction rate should, however decrease as the experiment progresses, this is because as the reaction time increases the number of HCL acid molecules present will decrease as they have reacted to form water, calcium chloride and carbon dioxide as shown in the balanced equations below. Though most boards had similar claims, they often differed in what evidence they chose to present. Collision theory explains how chemical reactions occur and why rates of reaction differ The timer starts after this initial swirl. In this coursework I am going to investigate what effect the change in acid concentration has on a chemical reaction You repeat the experiment with different concentrations of sodium thiosulfate or hydrochloric acid to see their effect on the rate-speed of the acid promoted decomposition of sodium thiosulfate to form a sulfur precipitate. However you decide to do it, the general approach to this experiment goes something like this: 1 Using a Sharpie, draw a black X on the bottom outside of each beaker. What is our dependent variable? This provided a great opportunity to talk about the benefits of qualitative evidence as well. Continue timing until no more gas appears to be given off. This reaction and the implementation of this natural clock can be seen below in a Flinn video2. What are we going to do with our data once we have it? The more concentrated the reactants, the more chance of a successful 'fruitful' collision.
The total volume of each solution should be the same in each beaker. It is acting as a catalyst.
I will do so by timing the reaction of Sodium Thiosulphate with an acid. With these results, the effect of temperature on the rate of reaction will be investigated.It is acting as a catalyst. In this coursework, I will include background knowledge, prediction, safety, results, calculations, graphs, an analysis, conclusion and an evaluation. Scientific knowledge: Marble chips erode when they are exposed to acid rain or pollution. For a reaction to occur, particles must collide. If you double the concentration of a reactant, the rate of reaction doubles. The first factor is: Temperature of reactants: When the temperature increases the particles move around faster because they have more energy This can be explained using particle collision theory by envisaging twice as many particles in the same volume will collide twice as frequently. Where their boards differed the most was in their reasoning, which is meant to have them justify why their evidence makes sense based on known scientific principles. To improve my experiment and to gain more accurate results I would use measured blocks of calcium carbonate rather than the marble chips as the varying size of these may have affected the reaction speed because of reasons explained about surface area in my introduction. In addition to this, the effects that concentration and temperature has on the rate of reaction were determined. Overall I think that my results were accurate and the test was reasonably fair although some anomalous results were obtained as shown highlighted in results tables and graphs but were few and far between. Enzymes such as Catalase are protein molecules that are found in living cells. Investigate the effect of temperature on the rate of reaction.
Pour the acid into the cm3 conical flask. The PowerPoint that I used to help facilitate this discussion can be found as Supporting Information at the bottom of this post if you are logged in to ChemEd X, but the general theme followed these questions: What is our independent variable?
In this coursework I am going to investigate what effect the change in acid concentration has on a chemical reaction All tables have been plotted as graphs to show any further patterns.