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1.2 conservation of mass answer key
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The question posed for the conservation lab was: what happens to the mass of a system in a chemical reaction? When new substances are produced in a reaction we say a chemical change has occurred. These changes are very difficult, sometimes impossible, to reverse. Atoms are not created or destroyed in a chemical reaction, they are just rearranged from the reactants to form the products. This is the reason why symbol equations must be balanced. If a chemical reaction is completed in a closed system (when nothing extra can get in and nothing can escape), then the mass will remain constant. But, if the chemical reaction happens in an open system (where air can get in and out), then mass may appear to change. We first took the mass of a plastic
If the relative amount of reactants is altered, then the limiting reactant may change accordingly. For example, a balanced chemical equation of a certain reaction specifies that an equal number of moles of two substances A and B is required. If there are more moles of B than of A, then A is the limiting reactant because it is completely consumed when the reaction stops and there is an excess of B left over. Increasing the amount of A until there are more moles of A than of B, however, will cause B to become the limiting reactant because the complete consumption of B, not A, forces the reaction to cease.
A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube.
A good example would be the experiments with the concentrations of 20% to 60% concentration results to show the change. In the 20% concentration I noticed a decrease in the percentage change in mass for the experiment the percentage was _____ while for the concentration of sucrose 60% the change was _____ we can see that the percentage change in mass is decreasing thus we can conclude that the difference of the initial from the final and as it gets greater that means the mass of the potato changed massively.
In exercise 1, I hypothesize that the most soluble pigments in the solvent will move furthest on the chromatography paper.
Mass of O = Mass of crucible, cover, KClO3 and MnO2 after heating (Step # 11) - Mass of crucible, cover, KClO3 and MnO2 before heating (Step # 5)
Chemical kinetics is a branch of chemistry that involves reaction rates and the steps that follow in. It tells you how fast a reaction can happen and the steps it takes to make complete the reaction (2). An application of chemical kinetics in everyday life is the mechanics of popcorn. The rate it pops depends on how much water is in a kernel. The more water it has the quicker the steam heats up and causes a reaction- the popping of the kernel (3). Catalysts, temperature, and concentration can cause variations in kinetics (4).
The purpose of the lab is to measure the biological diversity to assess the overall health of local streams. The more diverse the stream is with insects the healthier it is. Benthic macro-invertebrates are organisms that live underwater in streams. The Shannon diversity index is another index that is commonly used to characterize species diversity in a community. We also used an EPT index which ultimately measures the quality of the water based on the absence or presence of certain benthic macroinvertebrates. The benthic zone is the ecological region at the lowest level of a body of water. The Hester-Dendy sampler where aquatic macro-invertebrates will colonize the spaces between the rough textured plates of the sampler. The National
To start off the lab, my group members and I examined three different types of soil. First, we looked at the garden soil, then the forested soil and lastly the wetland soil. The purpose of this study was to determine the relationship between the carbon dioxide levels produced in the soil and the time. Overall, the higher the carbon dioxide levels, the healthier the soil is because the carbon levels have a direct tie to the amount of organisms living in the earth. If there was no respiration, the soil would essentially be dead.
I must use the same amount of enzyme each time I do an experiment so I
Laboratory Assignment 2 was a lab designed to teach our teams how to use the Engineering Design Process. By using this process our team will learn how to formulate a real world answer for a problem found in this lab. The problem we needed to solve was what is the best vehicle for transporting root beer kegs with limited time and only a ¼ gallon of fuel.
The purpose of this lab was to see firsthand the diffusion of a substance across a selectively permeable membrane. Diffusion is the movement of molecules from an area of high concentration to an area of lower concentration until both concentrations are equal, or as you could more professionally call it, equilibrium. This concept is one that we have been studying in depth currently in Biology class.
Our hypothesis for this lab was that the limestone will add mass because it is a sedimentary rock, and weathering and erosion break down a rock. Our data refute our hypothesis because we said it will gain mass when the limestone lost mass. The limestones Initial mass was 3.67, and after we put it in the oven the mass went down too 2.81. The mass went down by 0.86. Also, the graph above shows our data. The red line of the graph was the change in mass after we put it in the oven, and the blue line is the Initial mass. The red line doesn't move that much. After we put the rocks in the oven only one changed in mass. The Limestone changed 0.86 in mass, Quartzite changed 0.00 in mass, and Obsidian changed 0.00 in mass. By that data the oven did not really change the difference in mass. The blue line is our initial mass. Limestone was 3.87, Quartzite was 67.51, and Obsidian was 10.63. In the graph it shows the blue line going up. Our initial mass goes up, but our final mass stayed the same besides the limestone changed by 0.86. In the graph there were two trends. One goes up, and the other one basically stayed the same. The initial mass had a bigger impact because we used 3 rocks, and they were different masses. For the final mass the trend wasn’t that good because two of the final masses stay the same at zero, and the one that changed in mass was only a 0.86
Chemicals are always handled cautiously. They should always be handled with care to prevent accidents. CLEAPSS provide the regulations to the technicians stating what you should wear while handling a chemical depending on the strength of the chemical. This is to minimise the chance of any accidents occurring. They also advise the technicians on the equipment they should use and how to transport the chemicals safely and efficiently. This makes sure that the technicians are protected from the potential risks of handling chemicals and ensures that the chemicals are transported safely and efficiently. These procedures change in the presence of radioactive sources. The regulations come from the RPA then they go to the Derby council who will analyse these regulations and may add some of their own for improved safety then it reaches the School and they have to follow these regulations and sometimes add their own to prevent any possible accidents. After that process the RPA representative for the school has to complete a training course on the new regulations so that he can advise the school on the schools radioactive sources.
The main purpose of chemical engineers are to aid in the processes of turning raw materials into useful products such as plastics, chemicals, or even medicine. Since chemical processes are involved in a plethora of fields, chemical engineers have a wide range of industries that employ their services. Some of these industries are energy, food, oil and gas, medicine, plastics, consumer goods, or even civil jobs such as water treatment. This wide range of industries means that every chemical engineer may have a vastly different job from another that may work just down the road at a different job site. However, chemical engineering duties have many similarities no matter what career they are pursuing.
borate) and 1.0 g. of sodium hydroxide in 20 mL of warm water. It may