Wesley College
IB Chemistry IA: Energetics
Candidate: Jacob Savarirayan
Candidate number: 0006120082
Design:
Focus problem: Investigating the relationship between the relative molecular mass a primary alcohol and the respective enthalpy of combustion for that alcohol.
Independent, dependent, and controlled variables:
Variable Manipulating, measuring, or controlling variable
Independent variable The primary alcohol used Different alcohols (methanol, ethanol, and 1-propanol) will all be used within their respective spirit burners.
Dependent variable The amount (mass) of alcohol burned The dependent variable will be measured by taking readings of both the initial and final masses of the spirit burner (without the cap) thus the change in mass can be calculated.
Controlled variable 1 The change in temperature within the water in the metal can will be held constant at a change of 20oc The change in temperature is held constant at +20oC. This will be controlled to the best ability (see step 8, method). This is predominantly controlled to allow for consistency within the energy gained by the 100cm3 of water, and to maintain a consistent error in temperature change.
Controlled variable 2 The equipment used The equipment used throughout the experiment will be the same, as will the setup. This will be further controlled by performing every trial within the same approximately 75 minute period, thus eliminating the need to re-setup the apparatus. This control ensures that
The aim of the experiment was to find out how changing the mass effects the rise of the temperature of water.
In the lab the total volume of solutions used is kept constant in all the trials so that the temperature change remains directly proportional to the amount of reaction that occurs as well to the extent of the reaction.
Planning My aim for this experiment is to see the energy produced from different alcohols. This investigation involves burning alcohol in the air. ‘GCSE Chemistry’ by B.Earl and L.D.R Wilford says that "alcohols form, another homologous series, with the general formula Cn H2n+1OH ". The alcohol reacts with the oxygen in the air to form the products water and carbon dioxide.
13. The temperature of the water was measured prior to the tube being placed in it and the temperature of the Hydrochloric Acid was measured after it 's temperature had adjusted.
You have the mass of water from calculation #9, the specific heat of water is 4.184 J/g(oC), and the temperature change of water
The control experiment for this investigation will be the experimental setup of 5 trials using 5oC as the temperature. All the steps in the method will be followed.
Variables: In this experiment, the temperature (in degrees Celsius) of the chemicals is the independent variable. To change the temperature, the materials are placed in a bath of water being heated by a hotplate.
The purpose of this lab is to find if the mass changes when you galvanize and put a penny in the flame of a Bunsen burner introducing it to heat. In this lab, you galvanize eight pennies to silver and then heat up four of the silver pennies and make it into brass with the Bunsen burner. The independent variable in this lab is the penny because we have control over of what kind of penny we use rather it be new, old, dirty, or clean. The dependent variable in this lab is the mass of the penny because we are measuring the mass of each penny. Finally, the constant in this lab is the sodium hydroxide because; we use the same amount throughout the whole entire lab.
In this experiment, we investigate the change in temperature caused by adding a chemical substance into the water and dissolving it. The results recorded in the table below show that our hypothesis is correct.
The dependent variable is rate of fermentation, which will be measured by the amount of carbon dioxide produced.
This experiment shall be repeated twice or more to enhance accuracy of the results obtained. Besides detecting systematic errors, this experiment would aid on the technique and understandings to the correct use of these equipments.
Mass of water x 4.2 (water’s specific heat capacity) x temperature change = energy transferred from the fuel to the water
The aim of this experiment was to test the heat of combustion over a period of time, and the energy required to combust alcohols with different carbon chain levels. It was hypothesised that the higher the carbon chain of the alcohol present, the faster the heat of combustion will occur. Meaning more energy will be released for a higher carbon chain. After calculating the results from the experiment it was found that the hypothesis was partially supported. The reasoning for this is as the alcohol that posses a higher carbon chain, generally increased there reaction rates. However there were a few exceptions to this rule.
To achieve this, the final value from each thermocouple was set to be equal to the warm water bath temperature (370C), and the initial reading was set equal to the ice water bath temperature. Thus, for each thermocouple an equation was obtained using the two points to convert voltage readings to temperature. An example of the calibration for one of the thermocouples is shown in Appendix II.
Purpose: You will determine the molar heat of neutralization of 1.00 M HCL and 1.00 M NaOH in Kilojoules.