Energy Change in a chemical reaction. Throughout this investigation I will try to figure out the energy difference between different compounds reacting with water in a solution while it is being heated up.

Variables

Independent Variables

Temperature (This variable was controlled to keep the three separate experiments valid as the experiment was conducted to figure out the factors that affected the rate of which energy is transferred through a reaction so this variable must be kept equal.

Dependent Variable

Time (This variable was dependant on the temperature as it was one of the factors that was investigated upon as the experiment was conducted to figure out the factors to which affect the amount of time that it takes the solution to reach a particular temperature)

Materials

- (3) Beakers (250ml)

-Hydrochloric acid (10ml)

-Magnesium Powder (10g)

-Water

-Bunsen Burner

-Matches

-Stopwatch

-Thermometer

-Bunsen Burner stand

Method

1. Poured 150 ml of water into a beaker and heated it up to 70 degrees Celsius with a Bunsen burner, recorded the temperature every 30 seconds until it reached 70 degrees Celsius.
2. Poured 150 ml of water into a beaker and added magnesium powder (5g) to create a solution and heated it up to 70 degrees Celsius with a Bunsen burner, recorded the temperature with a thermometer every 30 seconds until it reached 70 degrees Celsius.
3. Poured 150 ml of water into a beaker and added magnesium powder (5g) and hydrochloric acid (10ml) and heated it up with a Bunsen burner, recorded the temperature with a thermometer every 30 seconds until it reached 70 degrees Celsius.
4.  Recorded the data

Data

Regular Water

Hydrochloric acid + magnesium powder + water (solution)

Water + magnesium powder (solution)

The data above shows the different energy levels in each of the solutions while it is heated up to 70 degrees Celsius. The amount of time that is required to heat each of the solutions to 70 degrees is also shown as a variable as the amount of time varies with the solution as for example water is shown to rise to 70 degrees faster than a water + magnesium + hydrochloric acid solution and it can be said that the rate of energy change is higher.  

Conclusion

In conclusion the leading factor that affects the energy change in a chemical reaction is shown to be time as the results show that the amount of time required to transfer energy to a solution was affected by the type of compound that reacted with water and created a solution, for example magnesium + water + hydrochloric acid which produced a solution of lower boiling point that of a regular water solution which affected the amount of time needed to heat the solution to 70 degrees. This is shown in the data as the solution with magnesium + water + hydrochloric acid is shown to take 5 minutes to reach 70 degrees whereas a beaker with water takes only 3 minutes, a big difference in boiling points. Time was also a factor in the reaction between water and magnesium as nothing happened during the reaction and the energy change was minimal and slow due to the temperature cap of 70 degrees.

Evaluation

The lab experiment was planned accordingly and the lab experiment went smoothly, however some of the results were unreliable and inaccurate, for example the reaction between magnesium and water occurred to slowly due to a temperature cap of 70 degrees which made the reaction between the two elements slower and less visible therefore the results from the test were somewhat unreliable due to limits. Another possible problem with the results could also arise from the accuracy of the results as the precise time was not given and the time was rounded to the nearest 30 seconds which could cause some issues concerning the accuracy of the experiment as results may differ. Overall the experiment could have gone better and the general idea of the experiment has succeeded, but some issues conflict the results.