This is a chemistry lab report example about viscosity. This chemistry lab report example can be used by students in order to figure out the general outline of their own chemistry lab report. The table of contents of this chemistry lab report is given below;
Aspect1: Define the Problem and Select the Variables
Chemistry Lab Report Background information:
Viscosity is defined as the internal resistance of a liquid to flow. Honey, corn syrup and shampoo are some of the liquids that have a higher viscosity and they are called as ‘thick’ whereas water and fruit juice are some of the liquids which have a lower viscosity and they are called as ‘thin. In other words, less viscous the fluid is, the greater its ease of movement.
To investigate the viscosity of different concentrated solutions.
How does viscosity vary with different concentrated solutions which are made of the same substance when the items that are used to prepare solution samples, apparatus and the solutions’ temperatures are kept constant?
Hypothesis: The viscosity of the liquids will be increasing with increasing concentration.
- Concencrations of solutions which are 10%, 20%, 30%, 40% and 50%.
- Time taken for the solutions of different concentrations to flown down the burette. By looking at the time taken, viscosity of the liquids can be compared to each other. Time taken for the solutions to flow down the burette will be measured by starting a stopwatch as soon as the the stopcock of the burette is opened.
- Type and brand of table salt. The table salt should be taken from the same pack of salt to prevent any differences that different table salts can make.
- Type and brand of burette.
- Temperature of the environment. (The experiment will be carried at room temperature which is 25,00 ±0,010C)
Aspect 2: Controlling Variables
Different brands of table salts can include different ingredients even if they are both table salts, thus any difference in table salts can affect the viscosity of the samples and decrease the accuracy of the results. By taking the salts for all of the sample solutions from the same pack, any inaccuracies in viscosity can be prevented.
The viscosity is determined by measuring the time taken for the solutions to flow down the burette. The surface of the burette has an effect on the amount of time taken for the solutions with different concentrations to flow down the burette. There can be some differences between the surfaces of different types and brands of burettes, so the same type and brand of burette should be used because and if the type of the burette is changed the time taken even for the solutions that have the same concentration can vary in each trial. In this experiment, the same burette will be used for each trial to prevent any inaccuracies.
Temperature is a factor that affects viscosity. If the temperature of the environment, where the experiment is carried, changes, the viscosities of the solutions change as well. So, the temperature of the environment should be kept constant to prevent any differences. In this, experiment, same environment, which is a laboratory will be used for each of the trials, thus the temperature will be kept constant.
- Tap water: Used in preparing the mixture of water and salt.
- table salt(10gr): Used in preparing the mixture of water and salt.
- Beaker (50ml): The mixtures of water and salt is collected in the beaker.
- Stopwatch: To measure the time taken for the mixture of water and salt to run down the burette.
- Stirring rod
- Stand: To hold the burette.
- Clamp: To hold the burette.
- Balance: Used to measure the mass of the samples of salt.
- Prepare salt-water solution of %10.
- Stir the mixture by using a stirrer to get a homogenous mixture.
- Take a stand with a clamp on it. Put the stand on a table and place a burette on the clamp as it makes an angle with the surface of the table, as shown in Figure 1.
- As the mixture of salt and water is stirred enough and it becomes homogenous, pour the mixture into the burette.
- As soon the mixture is poured into the burette, start a stopwatch and record the time taken for solution to flow down the burette and go out of the burette totally.
- Take three trials and record the data in a proper table.
- After being done with %10 solution, repeat the same method with 20%,30%,40% and 50% solutions.
To prepare a 20% solution, add 2 grams of table salt to 8 grams of water
To prepare a 30% solution, add 3 grams of table salt to 7 grams of water.
To prepare a 40% solution, add 4 grams of table salt to 6 grams of water.
To prepare a 50% solution, add 5 grams of table salt to 5 grams of water.
As the experiment is carried on, the data obtained from the experiment should be recorded by using Microsoft Office Excel. After recording the data, as three trials will be taken for each sample solution, the arithmetic means of the trials should be taken by adding all the three data obtained from the trials and dividing the sum to 3 since there are three trials. The more time taken for the solution to flow down the burette, the more viscosity the solution has. As the mean value of time taken for each sample solution is worked out, the graph of concentration of solution versus time taken to flow down the burette should be will be drawn to make a conclusion about the effect of concentration of a liquid on the viscosity of the liquid.