Essay, Pages 4 (876 words)
The purpose of this experiment was to identify whether density is an extensive or intensive physical property. By using water displacement, the volumes of the paper clip samples were measured and the masses were obtained by using an electronic balance. Each mass and volume was unique to their sample so by using their values, density was used to identify substances in the lab. After conducting the experiment, the results showed that there was a positive slope between the different paper clip samples’ masses and their volumes.
It was concluded from this pattern that density is an extensive property.
In science, there are two physical properties that are used to classify certain substances; extensive and intensive. Extensive physical properties are properties whose values vary directly with mass. (“Thermodynamic Properties” 2012) Therefore, they rely on the sample’s mass.
Intensive physical properties are properties that are independent of the amount of mass. (“Thermodynamic Properties” 2012) Therefore, they do not depend on the sample’s mass. One physical property that was investigated during an experiment was density.
Density is a physical property of matter that can be measured by dividing the matter’s mass by its volume. The purpose of the experiment was to answer the following question: Is density an extensive or intensive physical property? To answer this question, the densities of paper clip samples were calculated using their masses and measured volumes obtained from a water displacement technique. If the experiment showed that the sizes of the samples affected the calculated densities, then density would be an extensive property since it would be relying on the samples’ masses.
If density is an extensive property, then the masses of the different number of paper clips will affect the calculated densities because density depends on the mass of the paper clip samples.
Materials and Methods
During the experiment, an electronic balance, graduated cylinder, paper clips and weighing paper were used. The mass of five paper clips was measured with the electronic balance and was recorded. 30.0 mL of water were poured into a graduated cylinder and were recorded as the starting water volume. The paper clips were then placed into the graduated cylinder and the ending water volume was recorded. To calculate the volume of this sample, the starting water volume was subtracted from the ending water volume. The density of the five paper clips was finally calculated using the formula, d= massvolume. This procedure was repeated for each paper clip sample.
The mass of five paper clips is 4.9 grams, the mass of 9 paper clips is 8.9 grams and the mass of 13 paper clips is 12 grams. Each paper clip sample started out with the same water volume; 30 milliliters. After using water displacement to measure the volume of each sample, the results were that the volume of 5 paper clips is 1.0 milliliters, the volume of 9 paper clips is 1.5 milliliters and the volume of 13 paper clips is 2.0 milliliters. Using this data, the calculated densities were 4.9 g/mL for 5 paper clips, 5.9 g/mL for 9 paper clips and 6.0 g/mL for 13 paper clips.
Density is a physical property that can be used to identify substances in a lab. The formula for calculating density involves finding out the mass of a substance as well as the volume. The results of the experiment showed that each paper clip sample started out with the same volume of water; however their different masses led to different volumes when the water displacement technique was used to measure them. Therefore, each paper clip sample had a unique density. This showed that densities can be used to identify substances in a lab.
Water displacement is a technique used to measure the volume of substances by seeing how much water the substances displace or push aside when they are placed into a graduated cylinder. During the experiment, this technique was used to measure the volumes of the paper clip samples.
The density of pure water at room temperature is 0.9907047 g/cm³. The measured density of pure water was concluded to be 0.99 g/mL from the results of a separate experiment.
After the experiment was conducted, the results showed that density is an extensive physical property. The differences between the masses of the samples affected the calculated densities because although the ending volumes were different, each sample started out with the same volume of water. This was because each sample had a different mass. This was what led to the conclusion that density is an extensive physical property.
The conclusion does support the hypothesis however one source of error that may have affected the experiment’s results was the durability of the paper clips. The material they were made out of may have eroded away when water displacement was used to measure the volume of the paper clip samples. This would have affected the size of the samples. An improvement that could be made to this experiment based on this error is using a different sample. Instead of paper clips, pennies could have been used because pennies are made out of copper, which is a heavier metal than the mild steel paper clips are made out of. This would’ve eliminated the problem of mass loss during the experiment.