How does Concentration affect the rate of reaction between Magnesium and Hydrochloric acid?

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How does Concentration affect the rate of reaction between Magnesium and Hydrochloric acid?

Secondary resources:

Chemical reactions only occur when reacting particles collide with each other, with sufficient energy to react, this is called the collision theory. The minimum amount of energy required to cause this reaction is called the Activation energy. There are four main factors which affect the rate of reaction. The first factor is:

Temperature of reactants:

When the temperature increases the particles move around faster (because they have more energy). Because the particles are moving faster , they are more likely to collide. When the temperature is low, the particles are slower and they also collide less. The temperature drop lowers the rate of reaction.

Another factor is:

Concentration of the reactants:

Concentration effects the rate of reaction because if there is more of a substance, that means there is more particles. If there is more particles, there as an increase number of collisions and an increased rate of reaction. If there is less of a substance, that means there is less particles, therefore there will be less collisions and an decrease in the rate of reaction.

Another factor is:

The use of a catalyst:

A catalyst is a substance which increases the rate of a chemical reaction, without being used up in the progress. Catalysts are specific, I.e. different reactions need different catalysts. A catalyst lowers the amount of energy needed for a successful collision, so more collisions will be successful and the reaction will be faster . Also it provides a surface for the particles to attach to, therefore increasing the chances in colliding and also increasing the rate of reaction.

The last factor is:

Surface area of solid reactants:

If there is a bigger surface area there as in increase of collisions and also an increase in the rate of reaction, because reactions can only take place at the exposed, outer surface of the solid. If there is a smaller surface area there is less collisions, therefore there is a decrease in the rate of reaction.

Aim:

My aim for carrying out this investigation is to find out whether concentration effects the rate of reaction between Hydrochloric acid and magnesium metal.

Mg+2HCL ---- MgCl +H

Magnesium +hydrochloric acid ---- Magnesium chloride +hydrogen

Pre-test:

I have decided to use the water displacement method to collect the gas. While carrying out my pre-test, I performed experiments with different amounts, times, lengths etc in order to establish the most appropriate quantity.
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I have decided to use magnesium granules instead of magnesium strips and magnesium powder because when I experimented with magnesium strip It took way to long for the gas to be collected. When I experimented with magnesium powder the gas was collected to fast. So I decided to use magnesium granules because the time of the gas to be collected. As you can see the results below match my statement.

Magnesium (g)

HCA (cm)

H20 (cm)

Time (s)

0.1g (granules)

20cm

0

2.38

0.1g (strip)

20cm

...

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