Investigating the effect of varying concentration on the reaction between magnesium ribbon and hydrochloric acid

Investigating the effect of varying concentration on the reaction between magnesium ribbon and hydrochloric acid

Aim

It is to tell how the reaction between magnesium and hydrochloric acid will be effected if we change the concentration of hydrochloric acid.

Introduction

In the experiment the magnesium reacts with the hydrochloric acid to create magnesium chloride and hydrogen. The balanced formula for this is: Mg(s) + 2HCL(aq) MgCl2(aq) + H2(g)

Magnesium + hydrochloric acid Magnesium Chloride + Hydrogen

Magnesium will react with hydrochloric acid, because it is higher in the reactivity series than hydrogen. The magnesium displaces the hydrogen in the acid, so it forms magnesium chloride and hydrogen gas.

Magnesium strip

Hydrochloric acid particles

There are many variables that I can change, which are the temperature and concentration of the hydrochloric acid, and the mass and the surface area of the magnesium strip. This is all true because they all link to the collision theory of particles colliding with enough energy to make a reaction. It is based on the idea that for a chemical reaction to take place, the reacting particles have to hit each other hard enough to break or form new bonds. This is called a successful collision. When particles get stimulated or increased in number, the reaction will increase in rate because faster collisions will take place making more successful collisions.

This diagram shows five solutions hydrochloric acid and magnesium ribbon that are reacting. The arrows represent a simplified way to show how many successful collisions occur each second; therefore the more arrows there are, the faster the rate of reaction. They show how different factors can affect the rate of reaction against t...

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...at are very hard to keep constant so it would have been helpful to repeat the experiment again or even more. The syringe could have stuck on the barrel around it giving me lower readings on curtain points or when the reaction stopped. I should have put some lubricant around it to stop this from possibly happening.

Further Work

I could test the concentrations for the ones in between like 0.25 and

0.75 to see how the rate of reaction changes. I could also change the acid reactant to sulphuric acid or phosphoric acid to see and compare the results with different molecular make-ups. The other reactant that

I could change is the type of metal I use. Using the less reactive metals like zinc, aluminium, iron or lead enables me to test the higher concentrations like 3M or 4M because the reaction will go slower so I will be able to read the results off the syringe properly.