Hydrochloric Acid As 3 Cm Of Magnesium example essay topic

An Investigation into what effects the rate of reaction between magnesium and hydrochloric acid. Aim: My aim is to do an investigation into how the concentration of acid affects the rate of reaction with magnesium. I must consider; "h How much magnesium to use "h What concentration of magnesium to use "h Must react within a reasonable time Prediction: In solutions of higher concentration particles arse closer together. Which means they have a greater chance of colliding. Because there are more collisions per second, the reaction rate if faster, making the time of reaction shorter. Therefore, because of this, I predict the higher the concentration, the quicker the reaction.

Preliminary Investigation: Diagram: Method: "h Set out the equipment as shown above. "h Cut magnesium into 3 pieces of 2, 3 and 4 cm "h Pour 30 cm 3 of 2 molar hydrochloric acid into a beaker. "h Pour 10 cm 3 into each test tube and put each of your different lengths of magnesium into each test tube. "h Time from when the magnesium is placed in the test tube until when it dissolves. "h Repeat this with different concentrations Results: 2 Molar 1 Molar 2 cm of magnesium 12.58 50.00 3 cm of magnesium 25.38 54.83 4 cm of magnesium 26.15 60.06 From my preliminary investigation I have found that a molarity of 0.33 reacted too slowly. I have also found that 3 cm of magnesium were a suitable amount to use, for a suitable time of reaction. Fair testing: To make sure my investigation is fair I must make sure I always use exactly 3 cm of magnesium. I must also repeat each concentration 3 times and take an average, so I have fair results. Finally I must make sure the magnesium is clean, by using sandpaper to take off any magnesium oxide that has formed on the magnesium. I must do this as oxide on the magnesium can effect the reaction time.

Controlling Variables: To control my variables I will need to keep the magnesium length used at a constant of 3 cm. I will also need to keep the temperature of the water constant and the amount of acid used at 25 cm 3 every time. Plan: For my main experiment I will use what I found in my preliminary investigation to plan what I intend to do. Firstly, I will use the same equipment as I did for the preliminary investigation.

I have decided to use 3 cm of magnesium and 2 molar hydrochloric acid as 3 cm of magnesium gave me the best results and I have chosen 2 molar hydrochloric acid because it will give me a larger variety of concentrations. I will always use 25 cm 3 of hydrochloric acid and change the amount of water added. I will use the concentrations: 0.3, 0.5, 1, 1.5 and 2 molar. I will put the magnesium into the conical flask and time from when the magnesium is put into the flask to when the reaction is over.

I will repeat each concentration 3 times, take the mean and plot the means onto a graph. Results: Vol. of acid! SSM!" Molar-ity New Molar-ity New total vol. Vol. of water nee-ded.

Time exp. 1 (s) Time exp. 2 (s) Time exp. S Spoor results!" . Analysis: From my result table and my two graphs I have found that the more concentrated the acid, the quicker the reaction between hydrochloric acid and magnesium. This is because of the theory of particles been more likely to collide, giving more collisions per second when the acid is more concentrated.

This theory is in my prediction in full and because of this theory my prediction is correct. My two graphs show this theory.