Mass Lab

In this lab, the purpose was to determine the stability of a substance after adding an acid or a base. The results claim that liver and buffer are the most resistance to change in pH. Looking at figure 3, buffer and liver both maintain a stable pH even with the addition of an acid or base. However, potato and water have less buffer in them since their pHs did change. In figure 3, the potato acid’s pH level decreased by two, and the potato base’s pH level increased by two. The level of pH of a water acid decreased by 4, while the water base’s pH increased by 5. These results all tie to the fact that buffer is a substance that maintains a stable pH; the presence of buffer in organisms help maintain homeostasis by binding or releasing hydrogen

The law of conservation of mass states that matter can be changed from one form into another, mixtures can be separated or made, and or substances can be decomposed, but the total amount of mass remains constant. Taking this law from a different view we can state that the total mass of the universe remains constant. Whenever matter undergoes change the total mass of the products will be the same as the total mass of the reactants. For example, in this experiment sodium hydroxide and copper sulfate, the reactants have a total mass of 21.4 grams. The total mass of the products, copper hydroxide and sodium sulfate, was 21.13 grams. The 0.27 grams was a result of the solution staying on the thermometer that was used to measure the temperature. This law was formulated in the end of the 18th Century. It marked the beginning of modern history.

Yes, because the solution seen was still blue meaning that not all the copper chloride was extracted from the beaker.

Other sources of errors maybe that the cube were placed too closely to surface of the beaker so its ability to absorb the solutions because the closest sides to each other could obstruct the process of osmosis by blocking their exposure to the solution or of the varying time at which the cubes were placed in the

The most prominent error for this lab is the actual mass of the product. The actual mass of the copper we obtained is greater than the theoretical yield. The actual mass of the copper is 2.436 grams and the theoretical mass is 2.343 grams. The percent yield exceeds 100% and there is a great percent error of 3.969%. The cause of this error could possibly be the result of the impurity of the product. The solid copper product was left in the oven to dry overnight. It is possible that not all of the water has evaporated from the solid copper which would greatly influence the mass of the product. Another possibility is the accumulation of particles from the atmosphere into the solid copper and onto the filter paper. While the product was wet, dust particles from the air could have been pulled into the moisture.

The purpose of this lab is to identify the molecular mass of the volatile liquid. The molecular mass needs to be identified because it is a property that helps determine a substance. Since the substance is volatile, or easily evaporated, the liquid can be converted into gas. As the substance converts into gas, the ideal gas law, PV=nRT, can be used to calculate the the number of moles. Once, the number of moles is calculated, it is used in the molecular mass equation, which is, molecular mass = grams /mol. The grams of the gas is taken directly by measuring the substance, and the moles is taken indirectly through the calculations of the ideal gas law. The result of the calculations should be the molecular mass of the substance.

The overall point of the lab was finding the concentrations by using a variety of formulas and even a graph that really pulled it all together. It doesn’t seem as if the proceedure leaves any room for errors, since it could be performed flawlessly if all the measurements are correct. Overall, finding the concentration of solutions and learning how to use and make a claibration curve was productive and

The initial mass of copper was recorded, and then compared with the mass of recovered copper at the end of the experiment. The reactions that occurred during this lab include; Metathesis reactions, which are biomolecular reactions that occur in water, Redox reactions or reduction-oxidation reactions in which electrons are transferred between reactants, Single displacement reactions, which are redox reactions where a metal replaces a metal cation from its salt, Combination reactions, which occur when two or more reactants produce on product and Decomposition reaction, which occur when one reactant produces two or more products. Table of Reactions Cycle Step # Equation Reaction Type #1 Cu(s )+ HNO3(aq)Cu(NO3)2(aq)

In this lab experiment, we determined the densities of two solid substances that have regular and irregular shapes by water displacement and dimension methods. For the regular solid substance, the value of density was 0.18g/mL, while for the irregular solid substance, the density was 0.22g/mL. Primarily, we wanted to understand the significance and the meaning of the density of a substance. We discovered that density does not vary on the size and the amount of the substance. Instead, it depends on the composition of the substance. Therefore, it is an intensive property. In order to find density of substances, we calculate the mass of these substances, and we divided them by their amount of values. The basic units for the measurement of density

For instance, water condenses to the sides of the beaker which results in the H2O not leaving the beaker completely, meaning, our results of the amount of moles of H2O in the substance isn’t completely accurate. Another potential source of error is the amount of time for the CuSO4*5H20 and CaSO4*XH20 to be heated. For example, with the CuSO4* 5H2O, after a couple of minutes of being heated, the beaker with the substance was taken off the electric plate in order to measure the mass but it was noticed that the CuSO4*5H2O wasn’t completely white, which affects the results of the amount of moles of H2O. Next, with the CaSO4*XH20, it wasn’t visually possible to know when all the H2O has left the beaker because there wasn’t a color change like the CaSO4*5H20. A guess had to be made of when the H2O was completely gone; it was not certain if the time of 20 minutes was enough time for the substance.

Error could have a direct relationship with the water level because as the water level increased, the amount of water displaced by the apparatus also increased. If the groups in the lab did not top off their apparatus during measurement to ensure the correct water depth, the reading would be incorrect. To improve the accuracy of the lab, groups should be taught proper lab technique before performing the lab, and weights below 1 gram should be

Science Lab Essay Light is everywhere. Surviving without light now days would be difficult. If we shine light at various transparent objects of varying density, the light will bend more when it moves through an object of greater density. I need to know how light behaves as it passes through objects of varying densities because I am stealing the painting of Mona Lisa. I will need to know how to deactivate the lights around the painting.

First, we weren’t informed about exact amount of solvents. The method said put a spoonful of solute, but a spoonful doesn’t define the exact mass. This might have impacted our data because when we put a lot of powder or less, solute can takes longer time to dissolve or dissolve right away due to small amount. Second, we were careless about the way we kept apparatus. For an example, we didn’t properly wash the spatula and stick during the experiment. Therefore, some chemicals might have left and caused contaminations in solvents and solutes. To improve limitations and possible source of errors, I can do several trials to improve accuracy in the

I am investigating the relationship between fat and energy in McDonald's food the graph below has some insight into the relationship.But to get the answers we have to go deeper.

On modern Unix systems, the extra privileges resulting from using the setuid or setgid bits on an executable can be dropped either temporarily or permanently. It is best if your program can do what it needs to with elevated privileges, then drop those privileges permanently, but that's not always possible. If you must be able to restore the extra privileges, you will need to be especially careful in your program to do everything possible to prevent an attacker from being able to take control of those privileges. We strongly advise against dropping privileges only temporarily. You should do everything possible to design your program such that it can drop privileges permanently as quickly as possible. We do recognize that it's not