Understanding Density, Mass, and Volume

• Table of Data and Hypothesis

The following states whether or not the substance will either float, or sink. The density level for water is 1 gram per cubic centimeter at 4 degrees Celsius. This means that in order for an object to sink in water, the density level must be more than 1 gram per cubic centimeter. The following bar graph shows the density level of each object, and how it compares with water. Based on this data, do you think that these objects will float or sink inside water?

Through this bar graph, we can see how big the differences are between the metals (iron, gold, and lead) in comparison to rubber, wood, ice, and foam. Based on this data which measures these materials in grams per centimeter3, we can already come to steady conclusions onto what the results are going to be:

For referencing purposes, water has a density of around 1 gram per centimeter. All of these are measured in room temperature.

• Lead will sink because it is a very heavy metal that has a density of around 11.29 grams per centimeter. 

• Gold will sink because it is also a very heavy metal that has a density of around 19 grams per centimeter- being the heaviest substance of them all.

• Iron will sink because although it is not as heavy as the others, it still has a density of 7.8 grams per centimeter- still exceeding that of water.

• Rubber, wood, and ice each have a density which is around 1 and more, aka the density of water- meaning that it is guaranteed to float. But, rubber may change because different types of rubber has different types of density levels- it just depends on what kind it is.

• Question ) Why did the water level change?

The water levels changing is a good example of multiple things. That first, everything occupies space- even air, and something as little as rubber. They all occupy space. In a lab setting, salt and sugar may not be visible to us, but over time as they are being dissolved within a solution, there will be a saturation point. Although it's not visible to us, everything- no matter how small- takes up space. Second, it shows us the true meaning of volume and mass. Volume means how much space something takes up. In the simulation, if we do not touch anything, the total solvent of water takes up 25.5mL. When we add things inside of the solvent, its total volume will increase, because energy cannot be destroyed or created, only transferred. Therefore, this statement implies that water cannot be destroyed, but only transferred- and that is why the water levels saw an increase. It also relates to the particle model of matter. During the summertime, particles expand and take up more space- and therefore, things can expand. Water can expand, wood can expand,  etc. This lab well demonstrates how as things occupy more space, there is less space overall, which is the concept of density.

In density, objects that get added into our solvent will mean less space. Imagine an elevator. An empty elevator can be compared to our empty bucket of water, but, when people start coming in, there is less space. It's the same as density. With density, as we add more things and it begins to contract, there is less space within our solution, and therefore, it becomes dense. As we add in objects, the water level increases because there is a blockage between the particles. There is more particles in a same given amount of space, and therefore, the water needs to expand in order to maintain its capacity by pushing out the water to maintain equal volume as before. The density of an object is the amount of matter packed into a given volume. A high density object will be heavier for its size than a low density object. When a dense object is placed in water, it displaces a greater volume of water than a low density object, which means that the water level changes more when a dense object is placed in it. This is because the dense object takes up more space in the container, leaving less space for the water.

• Question ) What could the ??? substance be?

It could quite literally be anything. But, taking in the clues- we know that it has a mass of 18.58 grams, a volume of 31.2 mL, and has a density level far greater than water. Uranium weighs around 19 grams per cubic centimeter, which is its density. Because it has a mass similar to certain types of certain types of metal, I can conclude that it is a type of metal, that could be uranium considering their similar mass. It is not possible to determine the identity of a substance based on its volume and weight alone. There are many different substances that can have a volume of 5.7 mL and a weight of 18.5 grams, and without additional information, it is impossible to determine which one it is. The density of a substance, which is the ratio of its mass to its volume, can provide more information about its identity, but even then, there may be multiple substances that have the same density. To accurately identify a substance, you would need to know its chemical and physical properties, such as its melting point, boiling point, and solubility in different solvents.

• Question ) What object can float with 2.5 g/mL?

2.5 g/mL is only around a 1.5 g/mL increase from the density level of water. Observing from our data, lead wasn't capable of floating before, but, it does have a very similar density level compared to water of around 1.5. Therefore, lead is going to be capable of flowing because the density level of our new liquid is now more dense than lead, unlike what we have observed with water. It is not possible for an object to float in a fluid with a density of 2.5 g/mL. This is because the density of an object must be less than the density of the fluid in which it is placed in order for it to float. Since 2.5 g/mL is a relatively high density, most objects will be denser than this and will therefore sink in a fluid with this density. There may be some exceptions, such as certain materials that are specifically designed to be less dense than water, but in general, objects will not float in a fluid with a density of 2.5 g/mL.

The Connection

Is there a direct connection between viscosity and density? Well, short answer- no. But, long answer- yes. According to scientific studies, viscosity and density does not have a direct relationship. Meaning density itself does not affect viscosity levels, but instead, what happens when particles become more attracted to each other does have a connection with viscosity. Density levels change with thermal energy levels. Thermal energy is the main contributor and plays the biggest role in both viscosity and density levels. Viscosity itself does not depend on density, but rather, it depends on thermal energy. A fluid with higher density will transition to turbulent flow quicker, and a fluid with higher viscosity will have that transition later. so in a sense, they are inversely proportional. 

Reading the data above, we can see that with crude oil, as we see an increase in thermal energy, we saw a decrease in density, meaning that particles are expanding, and that viscosity levels are decreasing- with less friction from the expansion of particles. Viscosity levels change not because of density, but because of thermal energy levels. We can see the same results in Decalin, a type of organic compound. We can see that density is decreasing with an increase in temperature, and we can see that viscosity is also decreasing as a result. While the temperature may have an impact on density, the opposite we expect may also happen. Take water, for instance. We expect ice to be more dense than water because the particles are closer together, but rather, ice is less dense than water as it floats on water. This is due to the hydrogen bonds that decrease attraction between particles, resulting in a less dense form in comparison to ice in its liquid state of water. 

So, in conclusion- if we see a difference in density levels, we can expect a change in viscosity as well. If we see a difference in viscosity, we can see a change in density level as well. But, these 2 aren't directly related to causation- but instead, they are more related to correlation. 

The viscosity of a fluid is a measure of its resistance to flow, whereas density is a measure of a substance's mass per unit volume. These two properties are unrelated, and a fluid can have a high or low viscosity regardless of its density. Water, for example, has a relatively low density of about 1 g/mL, but its viscosity varies with temperature and other factors. Water has a viscosity of about 1.0 cP at room temperature, but as it is heated, its viscosity decreases and it becomes more fluid. Honey, on the other hand, has a much higher viscosity than water but a similar density, at about 1.4 g/mL. This demonstrates that a fluid can have high or low viscosity, regardless of the density level.

1. Saturation, Pure Substance, and Super Saturation

Density is the measure of the amount of mass in a given volume. Looking at the image above, we can see that they all have the same volume. Although they have the same volume, their mass greatly varies. The pure substance has minimal particles which are very spaced out, while the super-saturated solution of water and sugar shows very compacted particles. Therefore, the third visual is the most dense substance- because there is more mass in a given volume compared to the others. This is just a visual, and does not represent the real depiction. As a solution becomes more and more concentrated, it reaches a point where it can no longer dissolve any more of the solute. This point is known as saturation, and at this point the solution is said to be saturated. When a solution is saturated, the particles of the solute are evenly distributed throughout the solvent, and there is no more room for the solute to dissolve. If more solute is added to the solution, it will not dissolve and will instead form a separate layer on top of the saturated solution. This is because the solvent has reached its maximum capacity for dissolving the solute, and any additional solute will not be able to dissolve in the solvent. We can refer this process to osmosis and diffusion, as well as dispersion. 

Water is a pure substance, meaning it only has around 1 kind of particle of Hydrogen and Oxygen. Because it has such a low concentration of particles, water is not very viscous, because to my theory- it's not a dense substance. If water had a volume of around 5 mL, the mass would probably be around the same of 5 grams- and 5 divided by 5 is equal to 1, which is the water's density level when measured at room temperature. For our saturated substance, we will be testing syrup. Syrup is a saturated sugar solution, which means that syrup is likely more dense than water. At 10 mL, maple syrup is around 13.7 grams per mL meaning that syrup has a density of around 1.37 grams per millimeter. Syrup has a pretty close density in comparison to water, with a density of around 1 gram/mL.  When we heat things up, the solubility increases because the particles expand, and more kinetic energy is seen. As a result, there is more space for more solutes to dissolve, and there is more contact between the solvent and the solute. Therefore, if we can heat up our substance, we can dissolve more than the estimated saturation point of water. With our super-saturated substance, it was able to dissolve 200-300 mL of sugar. This puts the density at around 6.5 g/mL, which is nearly quadtruple the amount of syrup, and 6.5x more than the amount of water through sugar alone. We can see that sugar drastically increased the water levels within our solution. View our official lab report for more specific quantitative data. Through this data alone, we can see that the more solutes we add, the more dense a solution becomes- mainly evident in our supersaturated solution. Saturation has a connection with density, but, what about viscosity?

While we do not have quantitative data about whether or not density and saturation affects viscosity, it is pretty evident that it does. As we were heating up our solution to create a super-saturated solution, the more sugar solutes that we added, the thicker the solution became and the harder it became to agitate. The more sugar we added, we can tell that it was super viscous. The viscosity of a substance is a measure of its resistance to flow. In general, the higher the viscosity of a solution, the more concentrated it is. This is because the more solute that is dissolved in a given amount of solvent, the more the solute particles interact with each other and with the solvent particles. These interactions cause flow resistance, which raises the viscosity of the solution. When a solution reaches saturation, it has reached its maximum concentration and is unable to dissolve any more solute. The viscosity of the solution will be at its highest at this point because there are the most solute particles interacting with each other and with the solvent particles. This increases the flow resistance, making the solution more viscous. Adding more solute to a saturated solution will not increase its viscosity, because the solvent has reached its maximum capacity for dissolving the solute and any additional solute will not be able to dissolve in the solvent. When we add more solute, the more particles there are- and more friction between them. Especially in a super saturated solution, there are less space for the particles to move around (more dense), and the more interactions between whom. Adding more solute to a saturated solution will not increase its density or viscosity, because the solvent has reached its maximum capacity for dissolving the solute and any additional solute will not be able to dissolve in the solvent.

Experimenting with density, viscosity, and saturation can introduce a number of flaws and errors. The temperature of the solution can affect its density and viscosity, which is a common issue. As a solution's temperature rises, its density and viscosity generally decrease, making it difficult to compare the properties of different solutions. Another potential issue is that the methods used to calculate density, viscosity, and saturation can be inaccurate. For example, measuring the volume of a solution with a graduated cylinder can be difficult and inaccurate, especially if the solution is viscous and does not flow easily. Similarly, using a balance to determine the mass of a solution can be beneficial, but if not calibrated properly can result in inaccurate data and outcomes. Additionally, the properties of a solution can change over time, especially if the solution is not stored or handled properly. This can make it difficult to compare the properties of different solutions or to accurately reproduce the results of previous experiments. Overall, it is important to carefully control the variables in experiments involving density, viscosity, and saturation in order to obtain accurate and reliable results.

In conclusion, yes, viscosity, density, and saturation are all connected, though not reliant on each other.