Thermodynamics- Enthalpy of Reaction and Hess’s Law December 5‚ 2011 Kylie Case‚ Emma McKee‚ Rebecca Smith Purpose: In this lab‚ the purpose was to verify Hess’s Law. Theory: Four main topics were covered during this experiment including enthalpy of reaction‚ heat of formation‚ Hess’s Law‚ and calorimetry. The first being enthalpy of reaction‚ ΔHrxn‚ which is the heat or enthalpy change for a chemical reaction. The energy change is equal to the amount of heat transferred at a constant
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Materials needed include 1 molar HCl solution‚ 1 molar NaOH solution‚ 6 test tubes‚ measuring pipette‚ 10ml graduated cylinder‚ 40 ml 3% hydrogen peroxide solution‚ straightedged razor blade‚ scissors‚ forceps‚ stirring rod‚ fresh liver‚ fresh apple‚ fresh potato‚ test tube holders‚ ice bath‚ warm water bath‚ and boiling water bath. A Place 2 ml of the 3% hydrogen peroxide solution into a clean test tube. Using forceps and scissors‚ cut a small piece of liver and add it to the test tube. Push it into the hydrogen peroxide with a stirring rod
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Pg1Pg1 SCIENCE EXPERIMENTS ON FILE ™? Revised Edition 5.40-1 Potato Battery Lois Fruen and Chelen Johnson Topic Construction of a battery Time 45 minutes to 1 hour Safety ! Please click on the safety icon to view the safety precautions. Adult supervision is necessary for the soldering of the alligator
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: Osmosis in Quail’s Eggs Research Question What is the effect of different concentrations of sodium Chloride (NaCl) on the mass of the de-shelled quail’s eggs? Introduction Osmosis is an example of passive transport. Osmosis is defined as the movement of water molecules‚ down its concentration gradient‚ from an area of high water concentration (low solute concentration) to an area of lower water concentration (high solute concentration) through a selectively permeable membrane. Osmosis doesn’t
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Post lab The unknown solution 4055 was tested by the separation scheme in order to identify the four cations that exist in it. The cations found were Ag+‚ Ba2+‚ Mn2+‚ and Ni2+. When I added 5 drops of 3M NaCl to the unknown solution‚ we had some precipitate‚ we centrifuge and then we divided to two test tubes‚ and they were put in hot water and got confirmatory tested. The Ag+ appeared to be in the solution because it melted‚ however Pb2+ didn’t. With the rest of the solution we added Na2SO4 we had
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plant and animal cells are placed in a hypotonic environment‚ osmosis will occur. The structure of these cells determines the response to the difference in gradient‚ whether this be lysis (the explosion of cells due to the sudden increase in water pressure within the cell) in animal cells or turgor pressure (the pressure created by the increase in water pressure within the cell) in plant cells. Turgor pressure prevents further osmosis‚ which causes the water potential outside the cell to be lower
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Rachel Bohnenberger Professor Van Doorn ENVS 150-002 27 April 2015 GMOs Lab Report Introduction As the population of Earth increases exponentially‚ so does the demand for more food. One of the solutions to the question of how more food can be produced is Genetically Modified Organisms‚ or GMOs. There is an ongoing debate about whether or not GMOs are more beneficial or harmful to society. Some of the benefits to GMOs are: growing plants‚ such as corn‚ that are resistant to weeds and pests‚ larger
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of a Potato Mishal Hasan Abstract Students in Biology find it difficult to understand the concept of tonicity and osmolarity in a real time situation. In this investigation‚ several concentrations of sucrose were used to determine the osmolarity of a potato. It was found that the concentration of sucrose was close to 3.6 in the potato used showing that it was isotonic. Anything above caused the potato to gain weight showing that it was a hypotonic solution and anything below caused the potato to lose
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of the potato piece must be kept the same in each experiment primarily because they affect the surface area of the piece‚ and varying surface area could have a great effect on the rate of osmosis. This is because in an experiment where the potato chip has a large surface area‚ there is a larger area of partially permeable membrane and therefore more opportunity for water particles to pass through. I will keep the surface area the same by keeping the mass and length of the potato piece
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Membrane Transport Objectives ► Referring to energy‚ what two ways can substances enter a cell? What is active transport? What is passive transport? How is osmosis related to diffusion? How can we demonstrate active transport? How can we demonstrate Brownian movement? How can we demonstrate diffusion (2 ways)? How can we demonstrate osmosis (3 ways)? In terms of relationships between substances‚ how can we define “hypertonic”‚ “isotonic”‚ and “hypotonic”? What is the relationship between the size
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