Amy Smart 28/04/07
To Investigate The Factors That Affect The Rate of Reaction Between Magnesium Metal and Hydrochloric Acid.
Magnesium reacts with dilute Hydrochloric Acid to produce Magnesium Chloride and Hydrogen.
Mg2 (s) + 2HCl (aq) → 2MgCl (aq) + H2 (g)
Aim
To find which factors affect the rate of reaction between Magnesium Metal and Hydrochloric Acid.
Safety
Goggles
Fire retardant protective clothing
Hair tied back
Heat proof matt
Apparatus
Boiling Tube with bung and delivery tube,
Gas syringe – 100cm3,
Stand,
Measuring cylinder,
Emery Paper,
Magnesium Ribbon – 4cm,
Dilute Hydrochloric Acid 1.2 10cm3
Thermometer,
Bunsen burner and mat.
Method
We can record the rate of reaction by measuring at a regular interval, the volume of hydrogen collected.
To ensure a controlled experiment, all variables must remain the same throughout the procedure. I will change the temperature throughout this experiment.
My variables are length of magnesium ribbon and the volume of hydrochloric acid theses must remain the same.
Clean five, 4cm pieces of magnesium ribbon by pulling through emery paper.
- Using a measuring cylinder pour 10cm3 of hydrochloric acid into a boiling tube.
- Prior to starting the experiment fold the magnesium ribbon and balance on the upper part of a tilted boiling tube.
- Connect the boiling tube to a 100cm3 gas syringe.
- Ensure the reading on the gas syringe is zero before starting.
- Tilt the tube up, letting the magnesium drop into the hydrochloric acid.
- Gently rotate the plunger of the syringe to ensure it is unrestricted.
- Read the volume of the gas in the syringe after it has stopped.
- Heat 10cm3 of hydrochloric acid using a Bunsen burner with a heatproof matt underneath, to A 20oc,
B 40oc,
C 60oc,
D 80oc,
E 100oc.
Prediction
Increasing the temperature has two effects: it increases the frequency of collision and increases the proportion of collisions that are effective.
As the temperature is increased the particles move around more quickly. This causes them to collide more often, and therefore react more quickly.
As the temperature increases the particles have more energy. More of the collisions produce products, so the rate is faster.
The more collisions that happen between the particles in a given time, the faster the reaction.
When the temperature is increased the particles all move quicker. If they are moving quicker, they are going to have more collisions.
A graph of my prediction
Rate Rate is not
directly proportional.
Temperature oc
Preliminary experiment
After conducting a preliminary experiment I found that I needed to use a water bath to heat the hydrochloric acid. This means you can measure the temperature. I also found that I need to take more results e.g. 20oc 40oc 60oc 80oc and 100oc I can not go any higher because the water in the water bath will boil and the temperature does not change In the water it just turns into a gas. I also need to measure the volume of gas given off every 10 sec.
