This can be found by measuring the amount of reactant used up per unit of time, or by measuring the amount of product made per unit of time.
I know that when I react magnesium with hydrochloric acid together, hydrogen gas will be given off. Here are both word and chemical equations.
Magnesium + Hydrochloric acid = Magnesium chloride + Hydrogen
Mg(s) 2HCI(aq) MgCI 2 (aq) H 2 (G)
For my experiment I will be using the burette method instead of using a syringe or by weighing. I will be using the burette method because it is the most accurate out of the three.
The measurements I will be using for my experiment will be spread over 10 seconds. Therefore I will measure the volume of gas produced after every 10 seconds until the reaction has finished. I chose to spread my measurements over 10 seconds because it would be fair, because if I spread it over 5 seconds then there would be a short space between each reading n it will be too fast so I wouldn’t be able to record the right reading, and I wont spread it over 15 seconds because it would be too long and will have a far too big of a gap in between each reading.
For each different concentration of acid I will be repeating the experiments three times and then find the average of my result. Repeating the experiment will make the investigation fairer and more reliable. This is because if I have one bad result I can then level it out by finding the average of the three results, therefore my results will be more accurate.
Prediction
I predict that the higher the concentration of the acid the faster the reaction will be.
I predicted this because the higher the concentration of the acid the higher number of particles in a given volume, and if there are more particles, there will be more collisions. More collisions means a larger number of successful reactions, so therefore the rate of reaction will increase.
How I Will Make The Investigation Safe
I will make sure that this experiment is a safe one so I or anyone else doesn’t get hurt whilst doing the experiment.
In order to this a safe experiment people should do the following:
- Anyone with long hair should tie it back
- Everyone should wear goggles
- If anyone gets acid on their skin or eyes they should immediately wash it out
- Never throw acid around
- Don’t run in the laboratory
- Don’t mess around with sharp objects
- Always stand whilst doing the experiment
- Put bags under the table or some where, where no one will trip over it
Method
For my science coursework I am going to find out the rate of reaction between Magnesium and Hydrochloric acid.
To this is I must collect some reliable and accurate results by doing an experiment. As I said I will be using the burette method because it’s the most accurate way of doing this experiment.
The equipment I will be using is:
- A Burette
- Rubber tube
- Flask
- Stopwatch
- Magnesium
- Hydrochloric acid
- Sand paper
- Trough
- Measuring cylinder
The different concentrations of acid I will be using are:
- 0.5Mcl
- 1.0Mcl
- 1.5Mcl
- 2.0Mcl
- 2.5Mcl
After gathering my equipment I will set it up as shown below:
After gathering and setting up my equipment I will then start my experiment by doing these steps:
- Check the room temperature
- Put my safety goggles on
- Measure out 50ml of acid
- Cut 5cm of magnesium
- Put the 50ml of acid and the 5cm of magnesium in the flask and start timing
- Record the results after every 10 seconds until the reaction has stopped
Evaluation
I think my procedure was good because it gave me a set of results that proved my prediction was correct. I predicted that the higher the concentration of the acid the faster the reaction would be.
Conclusion
In my results table I can see a pattern; the stronger the acid the faster the rate of reaction is.
Acid Time when reaction stopped (sec)
0.5MHCl 80
1.0MHCl 60
1.5MHCl 40
2.0MHCl 30
2.5MHCl 20