All matter is composed of small particles, which are in constant movement. When two particles collide with enough energy, a change in election arrangement occurs forming a new chemical bond resulting into a chemical reaction. The speed of a reaction is called the rate of reaction. Some reactions can be very fast and others very slow it mostly depends on the concentration of a reactant. Increasing the concentration shrinks the space between particles resulting into an increase in the number of collisions. In most cases increasing the concentration of the reactants increases the rate of reaction but there are a few cases where increasing the concentration of one of the reactants had hardly any noticeable effect of the rate.
An experiment was conducted in class that measured the rate of reaction when different concentrations were used. When completing the class experiment only three different concentrations where used leading to an issue. The experiment was then modified to extend the number of different concentrations to five, to give a higher variety of results and evidence for the experiment.
The purpose of conducting this experiment was to determine how changing the concentration of one of the reactants would influence the rate of reaction. The aim means if changing the concentration of hydrochloric acid would increase the rate of reaction.
If the concentration of hydrochloric acid increases, then the reaction rate will also increase when the temperature and the measurements of reactants are kept the same. This outcome is expected because of the particle theory, which states that by increasing the concentration it will shrink the spaces between the particles resulting into an increase in the number of collisions ending up with an increased rate of reaction.
The original method was used as a foundation and basis for the new experiment. The original method involved three trials of 0.5M,1.0M,1.5M of hydrochloric acid and 50mL of sodium thiosulphate. The modifications that was made to the method was instead of only involving 3 concentrations of the hydrochloric acid in the experiment, 5 concentrations were used. The modification extends the results to provide a more justified answer to the research question.
Analysis and Interpretation of the Evidence:
Trends, Patterns or Relationships:
The evidence from the graph shows that when the X axis increases, the Y axis also increases. This intends to show that as the concentration gets higher, from 0.1m through to 2.0m of hydrochloric acid, the time for the reaction to finish accelerates as the concentration intensifies. This is demonstrated in the graph and the table of results, when the concentration of hydrochloric acid was at 0.1m it took average time of 96.09 seconds to fully react but as the concentration was then increased to 0.5m it took 49.80 seconds to fully react, being faster than the 0.1m. This pattern is continued throughout the data.