Recent Question/Assignment

I just need help with everything that is unanswered but Im sure all information is there already...
Practical Report – At home Data Analysis Task
Jess Hynes
Red = not complete yet
Yellow = Needs working (editing)
Green = complete
Purple = Information about the report
The purpose of this experiment is to see how temperature and concentration affect the rate of a chemical reaction.
describe what happens during a chemical reaction
When a chemical reaction happens, a change in the chemical bonding that holds atoms together causes energy to be more evenly distributed among the atoms in the rearranged state. The most likely state of energy is for it to be in thermal equilibrium with the cosmic microwave background, which means that it will radiate energy into space in a uniform manner (Aoki and Shimosaka, 2018). A reaction is similar to a -square dance- because the atoms switch places with one another. Sometimes a response requires a little -pushing,- in the form of a bit of burst of strategic energy to get it off the ground. However, the reaction will not always continue to a complete stop; instead, it will proceed until it finds an -equilibrium,- which is described in terms of probability (Aoki et al., 2019).
describe collision theory and how reactants interact to form products (needs figure + reference)
Collision theory was developed by Max Trautz and William Lewis in the early 1900s when they established that particles must collide with one another in position to react. The collision theory of chemical reactions says that the pace of a chemical reaction is related to the number of collisions between reactant molecules between two reactant molecules. The more often reactant molecules collide, the more frequently they react with one another, and the more rapid the reaction rate is. Only a tiny percentage of collisions result in effective collisions with other objects (LibreTexts, 2020). Collisions that are effective in causing a chemical reaction are called effective collisions. Reactant particles must have a certain minimum amount of energy to create a successful collision. The activation energy is the amount of energy that is required to start the reaction from scratch. Some reactant particles have this amount of energy in every sample of reactant particle (Stojanovska et al., 2017). The bigger the size of the sample, the greater the number of effective collisions and the greater the pace at which the reaction takes place. The temperature of the reactants affects the number of particles that have enough energy to cause a reaction. If the reactant particles do not have the necessary activation energy when they collide, they will bounce off of each other without causing any reaction (Durmaz, 2018). Trautz and Lewis had concluded that 1.) For a reaction to occur, particles must collide. 2.) The particles must be able to break and form new bonds with enough energy. 3.) They must collide in the right direction.
• describe the chemical reaction used in the experiment, including a balanced chemical equation
describe what a precipitation reaction is and how we can represent it as a chemical equation.
The Liesegang (periodic precipitation) phenomena is the oldest pattern formation. It was found and documented in 1896 by Raphael Edward Liesegang, a German scientist and photographer. Liesegang had discovered that two equation solutions are mixed in a precipitation reaction, resulting in a solid substance called the precipitate. As the reaction progresses, the ions from the reactants aqueous solution create an insoluble ionic compound, which is the cause of precipitation. Because the polar water molecules surround the individual ions of the salt, most ionic solids, such as salts, are soluble in water. Those that do not dissolve and go into solution create precipitates, which are solid products. These precipitates come in a variety of colours, which can assist scientists in figuring out what kind of precipitate is there. Net ionic equations are commonly used to represent precipitation reactions. Because all ions are cancelled out as spectator ions when all products are watery, a nett ionic equation cannot be stated. To identify if an equation is a precipitation reaction, it is when you have a double displacement reaction.
Example: (is this correct?)
Pb(NO3)2 (aq) + 2NaI(aq
When we join these two solutions, the ions can either combine in the same way they entered the solution or trade partners. In this situation, lead nitrate and sodium iodide could form, or lead iodide and sodium nitrate could form; to decide which will form, we must look at the solubility laws (“Notes on Precipitation Reactions - General Chemistry | CHEM 142 - Docsity,” 2021).
describe in the detail what is meant by a “clock reaction”. Include references to both a technique using iodine, and our technique that uses sodium thiosulfate. (Needs fixing because its “apparently a bit too complex”)
A clock reaction is another way of measuring rate. Clock reactions are a really good way of investigating the effect of concentration or the rate of reaction while also being simple to perform. The disappearance of a reactant, such as a sulfite in the Landolt reaction, controls the clock time in the traditional clock reactions. However, there are various types of clock behaviors that may occur. This article provides a brief overview of several instances. The clock time in the bromate-cerous reaction is regulated by the autocatalytic rise in the concentration of an intermediate molecule, HBrO2, which occurs during the process (Yan & Subramaniam, 2016). In the BL reaction, the induction time when the iodide ions concentration is measured looks different when the iodine and iodide concentrations are measured. This period should be referred to as the pre-oscillatory period. We have discovered an entirely new kind of clock behavior in the process of iodine oxidation by hydrogen peroxide: the clock begins to beep when another reaction disrupts the stable steady state of the hydrogen peroxide breakdown (Jusniar et al., 2020). The transitions between various dynamical states that all clock reactions entail go beyond their distinctions. The experimental curves can be analyzed by identifying time intervals with identical combinations of the time concentration profiles first and second derivative signs. This trend analysis can provide helpful information about the dynamical state transitions involved in the experiments (Jusniar et al., 2020).
You will need to record your references correctly in APA style
Hypothesis (I had to re start)
• 2 to 5 sentences explaining your prediction of what should happen in this experiment. You need to back this up with information from your introduction.
sodium thiosulfate (0.5 M) solution 2 x 50 mL conical flask
hydrochloric acid (1 M) solution hydrochloric acid (2 M) solution
cold water bath hot water bath
5 mL measuring cylinder plastic pipette (3 mL)
deionised water stopwatch
thermometer marker pens
white paper
1. Add 5 mL of deionised water to the conical flask, using the measuring cylinder.
2. Add 5 mL of sodium thiosulfate (0.1 M) solution to the conical flask, using the measuring cylinder.
3. Put the conical flask into a container of ice water for 1 to 2 minutes, until the temperature of the solution is 10°C. Record this temperature.
4. Remove the conical flask from the ice water and dry its base.
5. Draw a cross on a piece of white paper and place the conical flask on top of the cross.
6. Add 2 mL of hydrochloric acid (1 M strength) solution to the conical flask using the plastic pipette and use the stopwatch to time how long it takes before the solution has become so cloudy that you can no longer see the cross under the base of the flask.
7. Repeat steps 1 to 5, but use 2 M hydrochloric acid solution instead of 1 M hydrochloric acid solution.
8. Repeat steps 1 to 5, but use the hot water bath in step 2 instead of cold water. Put the conical flask in the hot water for 1 to 2 minutes, until the temperature is 30 °C.
9. Repeat steps 1 to 5, but use 2 M hydrochloric acid solution and the hot water bath in step 2 instead of cold water. Put the conical flask in the hot water for 1 to 2 minutes, until the temperature of the solution is 30 °C.
1M acid and cold bath – 12 minutes 2M acid and cold bath – 8 minutes
1M acid and hot bath – 2 minutes 2M acid and hot bath – 40 seconds.
Discussion – 2 pages maximum (had to restart)
• written as text, with no dot points and a new paragraph should be started for each new point.
• include a paragraph describing your results and relating them to collision theory.
• Refer to the student observations. In reference to these observations, in what ways could the experiment be improved to ensure that the results are accurate and consistent between groups
• describe several applications and everyday occurrences that can be explained using the concepts involved in collision theory and analysing the rate of reaction
Evaluation - Answer the Questions in Bold in reference to the following information
Alan and Belinda carried out some reactions using hydrochloric acid and calcium carbonate (marble chips). They did an experiment four times, each time changing one variable. The table below gives the conditions for each of the experiments:
Reaction A B C D
Volume of Acid (mL) 50 50 50 100
Volume of water added (mL) 0 50 0 0
Temperature (oC) 20 20 60 20
From your experiences:
Write the reaction that is most likely to produce the most gas. Explain your answer.
Determine which reaction is likely to be finished first? Explain your answer in relation to collision theory.
Which of these experiments is likely to be the control reaction? Explain why you think this is.
The was carried out and Experiment D was completed in about the same time as experiment B, but produced twice as much gas.
Alan said “Obviously there was an error in the measurement. Both experiments should have produced gas at the same rate as reaction D because they both use 100ml of solution. Acids have water in them anyway, so it makes no difference that there is 50ml of acid and 50ml of water.
Belinda said “Well, they have the same volume of solution, but its not the water that reacts with the marble chips it’s the acid. So reaction B really only has half the amount of acid as reaction D, so the results should be different.”
State who you agree with, why, and relate this to collision theory.
Conclusion (Was told too complex and had to re start)