Marble Chip Investigation
1.Set up the equipment as diagram shows. The measuring cylinder must be filled with water and then inverted into the tub.
2.Measure the quantity of hydrochloric acid and marble chips to the decided amount. Add water to the acid to change the concentration to what you need.
3.Take note of the amount of water in the measuring cylinder.
4.Put the marble chips and hydrochloric acid into the conical flask. Replace the bung and start the stopwatch.
5.Once the decided amount of time has passed, take note of the remaining amount of water in the measuring cylinder. Subtract this number from the one noted down in step three, this is the volume of gas produced.
6.Repeat experiment with at least 5 different concentrations of acid.
稡ung and delivery tube
稡oss head clamp
Hydrochloric acid is very corrosive, so care will be taken when handling it. Safety goggles will be worn throughout the investigation as the reaction could fizz violently and cause eye damage if it was to spit.
稢oncentration of acid
稴urface area of marble chips
稭ass of marble chips
稸olume of acid
The only variable that I will intentionally change during the investigation will be the concentration of acid. I will do my best to keep the other variables constant.
After carrying out the preliminary tests, the measurement I will be using are:
�0cm3 of each acid concentration
� of marble chips
The concentrations of acid that I will use will be:
To make it a fair test and make my results more accurate I will try and keep all variables constant except the concentration of the acid. This will include weighing the marble chips every time and trying to use lumps of roughly the same size to keep the surface area fairly constant as a change in surface area will affect the rate of reaction. I will try and avoid a change in temperature and I will use the same equipment throughout the tests. Each concentration will be repeated at least once to improve accuracy as an average can be taken.
The rate of reaction depends upon two factors, the number of collisions within a time between the reactants, and the fraction of these collisions that are successful. Therefore, the higher the concentration of the reactants, the higher the rate of reaction because there will be an increased number of collisions, this is called collision theory. However, for the reaction between the two reactants to be successful, they must collide with enough energy to react, the energy needed to react is known as activation energy. This can be shown on a graph like the one below, I believe this graph is similar to what the energy diagram would be for my investigation.
This shows that my chemical reaction will be exothermic, therefore it will release more energy than it uses to react. Therefore, at a higher concentration, there will be more reactions releasing energy in the form of heat that will enable more particles to reach their activation energy level and react. This shows that the rate of reaction will increase with the concentration of acid.
After having done some research I feel that I can make an education prediction concerning what will happen during my investigation. I predict that the higher the concentration of acid I use, the faster the rate of reaction will be. I think this because the higher the concentration is, the more acid particles there will be to collide with the marble chip with enough energy to cause a reaction as explained in collision theory. I also believe that the rate of reaction will increase with concentration of acid because the chemical reaction I am doing is an exothermic reaction. Therefore, it will release energy as the...
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