Rate of Reaction Between Marble Chips and Hydrochloric Acid

Rate of Reaction Between Marble Chips and Hydrochloric Acid

To investigate the factors which affect the rate of reaction

between marble chips and hydrochloric acid, with one in specific

detail.

Scientific knowledge:

Marble chips erode when they are exposed to acid rain or pollution.

Erosion is evident when you look at older marble buildings as in

certain cases the erosion take a long time. It is more likely to occur

in areas, where there is more pollution. This is because there are a

greater number of industries in city than in the countryside.

Especially the higher amount of cars which release carbon dioxide,

formed as a waste gas in reactions such as internal combustion.

Carbonic acid (the product of carbon dioxide and water) mixes with

acidic pollutants such as sulphur dioxide and oxides of nitrogen to

form acid rain. When this rain contacts the rocks, a chemical reaction

takes place, weathering the rock. Sulphur dioxide and oxides of

nitrogen produced by industries in the cities also increase acid rain;

hence, acid rain is more common in cities than anywhere else.

Marble is a metamorphic rock, which means that the rock consists of

inter locking crystals and the rock itself is very hard. To have

gained this state, the rock was compressed and heated over thousands

of years by tectonic activity.

Metal Carbonate + Acid Salt + Water + Carbon dioxide

Calcium Carbonate + Hydrochloric acid = Calcium Chloride + Water +Carbon dioxide

2 HCL (aq) + CaCO3 = CaCl2 (s) + H2O (l) + CO2 (g)

To speed up the rate of a reaction, you can:

* Add a catalyst

* Increase the temperature

* Increase the surface area

* Increase the concentration

These four methods all link in with the "Collision Theory"

The basics of Collision Theory:

Collision Theory relates to the number of molecules in the reaction,

the chance of colliding correctly and the correct amount of energy.

For a reaction to take place between two substances, their particles

must collide, so if more collisions occur, the rate of the reaction

increases. However only some collisions are successful. This is

because not all particles have enough energy to break bonds in other

particles. We can alter the conditions under which the reaction takes

place so that more collisions occur in a given period of time and so

that the rate will increase.

Catalyst...

... middle of paper ...

...very quick and therefore observed it

every 5 secs.

I was interested in this experiment when I first started. I was

interested in seeing changes in the reactants at the end of the

reaction. I was very satisfied when I found out that my predictions

were correct.

To furthur my experiment:

I could use sulphuric acid. This is a dibasic acid and its molecular

build-up is H2SO4 and hydrochloric acid is 2HCL, because of this I

would obtain different results. I could also use phosphoric acid,

which is a tribasic acid, and its molecular build-up is H3PO4, I would

also obtain different results if I used this type of acid. Nitric acid

is a monobasic acid but its molecular build-up is HNO3, which is very

similar to the molecular build-up of hydrochloric acid so the results

that I would obtain from using this acid would be similar to the ones

I already have, so I would not use this for any further experiments.

The reason I could use a different type of acid for any further work

is to find if there is a difference between them if their molecular

build up is different.

I could also use the less reactive metals of the reactivity series

(zinc, aluminium, iron and lead).