Science Essays

In order to create the sodium hydroxide solution, its pellet-form was dissolved in deionized water. The concentration of ethanol varied in each trial, with 25 mol% and 35 mol% concentrations used in the reactor. In order to determine the rate constant, 10 ml samples were taken every 10 minutes for an hour during the reaction […]

The purpose of this experiment is to measure the concentration of a sulphuric acid solution, which ranges from 0.05 to 0.15mol/dm?. To achieve this, I will use an alkali with a known concentration to titrate the unidentified sulphuric acid solution. The indicator phenolphthalein will be used to indicate when the acid is neutralized. The necessary […]

Concentrated hydrochloric acid is roughly 11 M. Pour out into a measuring cylinder about 2 cm3 of concentrated hydrochloric acid. Transfer it to a 250 cm3 flask and make up to the mark with water. Shake well. Put some pure sodium hydrogen carbonate or anhydrous sodium carbonate into an evaporating dish and heat gently over […]

Calcium is a mineral which is essential to the human body. In fact 1. 5% of the human body is made up of calcium, and not just the obvious uses such as bone and teeth formation but it is also a vital factor in many enzyme reactions, for example blood clotting. It also partakes in […]

Introduction An acid-base titration is a method of neutralizing strong acids. Unbeknownst to many, acid-base titrations occur on a daily basis. Our stomachs use acid to help us digest our food – approximately . 155 hydrochloric acid (HCl) with a pH of 2-3. When too much of this acid is formed in the stomach, heartburn […]

To determine and analyze the moisture content of a given sample using the Karl Fischer volumetric titration technique, the following steps are taken. The Karl Fischer volumetric titration method detects the moisture content in samples by reacting the iodine present in the Karl Fischer reagent with water in a 1:1 mole ratio. The reaction can […]

Title: The Factors Affecting Enzyme Activity Speeds Problem: How do the factors of temperature, pH level, substrate concentration and enzyme concentration specifically and significantly alter the rate of enzymatic reactions? Background Information: Enzymes are critical to the function of human life. They are the controllers of all the chemical reactions within our bodies – they […]

Introduction: The purpose of this experiment is to measure the effects of changes in temperatures and pH on enzyme activity in skeletal muscle, particularly the activity of lactate dehydrogenase (LDH). LDH is a glycolytic enzyme which converts pyruvate to lactate in the following equation: LDH Pyruvate+ NADH ? ————? Lactate + NADThe reaction above can […]

Number Objective Rates of Reaction Define the term rate of reaction. Describe suitable experimental procedures for measuring rates of reactions. Analyze data from rate experiments. Students should be familiar with graphs of changes in concentration, volume and mass against time. Collision Theory Describe the kinetic theory in terms of the movement of particles whose average […]

Various chemical tests Identifying ketones and aldehydes are used In this experiment in order to Identify an unknown carbonyl compound. The tests used are: 2,4- dinitrophenylhydrazone test, Tollen’s Test, Benedict’s Test, Chromic Acid Test, aka Bordwell-Wellman Test, Schiffs Test, and Iodoform Test. These classification tests provide results based on color change or formation of precipitation, […]

Friedel-Crafts acylation of anisole with acetic anhydride was used in this experiement to synthesize 4-methoxyacetophenone with the use of a reflux apparatus. Friedel-Crafts reactions can be done by alkylation, which involves mixing an alkyl or acyl halide with a Lewis acid, or acylation, which is done with acid chlorides or anhydrides(Lefevre). Acylation was used because […]

I did this lab to find out the differences between chemical and physical changes. I also did this lab to learn the signs that would indicate the chemical reactions and physical changes. I needed to learn the odor change, color change, bubbles or gas, irreversible, temperature changes and finger prints. By the end of the […]

Metabolism, which encompasses a vital sequence of biochemical reactions, is essential for the survival of all living organisms. During activities such as marathon running, the body relies on its fat and carbohydrate stores to generate Adenosine Triphosphate (ATP) as an energy source. ATP plays a significant role in various biological processes, including movement and molecule […]

Introduction According to C. C. Lai et al. (2005), the high cost of feedstock oil is a significant barrier for the commercialization of bio-diesel. However, research conducted by Sulaiman Al-Zuhair (2008) has demonstrated that waste-cooking oil (WCO) could be a viable alternative raw material for biodiesel production. One way to reduce the cost of bio-diesel […]

Introduction: Humans sometimes don’t know why phenomenon or things happen. They just accept it without knowing the cause of it. And there is no meaning in it if we just accept things without reasons. That’s why this experiment is conducted so that we may know how things happen in the level of cells. Objectives: 1. […]

Although we had a hypothesis about potato osmosis, the data we collected did not support the traditional definition of this process. According to convention, osmosis involves water moving through a semi-permeable membrane from an area with low solute concentration to one with high solute concentration. However, our results did not match this explanation. We expected […]

Introduction: This lab helps further our understanding of essential principles behind diffusion and osmosis. Permeability, concentration gradients, plasmolysis, water potential, and equilibrium were also concepts that were delved into in this lab. Understanding how diffusion and osmosis works is essential to understanding biology. Each time a cell has something move into or out of it, […]

Intro I am going to do an investigation into what concentration of sucrose solution would cause “Incipient Plasmolysis”. Theory Plasmolysis is the result of a (in particular) plant cell which has lost vast amounts of water. When this happens, turgor pressure within the cell has decreased to the point where the cytoplasm of the cell […]

Introduction The current food industry has come about through generations of cultural and technological developments, involving many aspects from food production to processing to retail before reaching the consumer. In this day and age, the highest level of quality and safety are expected from food products, and the market for value-added foods is ever-increasing. As […]

One dicotelydonous leaf was taken and approximately 1cm� of clear nail varnish was painted both on the adaxil (top) and abaxil (bottom) surfaces of the leaf. It was then left for approximately 10 minutes to dry and gently peeled off using a scalpel after the 10 minutes. The peeled nail varnish was then examined first […]

Our objective is to comprehend osmosis and its significance in the cells of living organisms, such as animals and plants. The experiment will yield proof reinforcing the concept that osmosis entails the transfer of particles from a solution with high concentration to one with lower concentration through a permeable membrane. It is vital to conduct […]

This experiment is to determine the role of water potential of tissues in plants most particularly the movement of water into and out of potato storage tissue so that the isotonic point can be identified.Prediction.Potato is a plant that contains more starch grains and immature chloroplasts in the plant cells. Thus it has a lot […]