Water from a variety of sources that receive precipitation is being sampled. Using a pH meter, the pH of water samples is being measured. In the first approach using titration methods in combination with pH measurement, the volumes of sulfuric acid needed for reaching two different pH levels are being measured. Difference in the volume of sulfuric acid used, is an equivalent for the amount of CaCO3 expressed in grams per (gL-1) in the analyte. Therefore the alkalinity of water samples is being calculated.
Add 0.1M HCl one drop at a time. Use the stirring stick and stir each time a drop has been added. Determine the pH after 5 drops have been added. Repeat the procedure until 30 drops have been added. 4.
Hydrate Lab The purpose of this lab is to analyze the percent water in a crystalline hydrate and to indentify the hydrate from a list of possible unknowns. The solid hydrate will be heated to remove the water, and the percent can be found by measuring the mass of the solid before and after heating. The hydrate will be indentified by comparing the percent water in the hydrate with the percent water calculated for the possible unknown. Before the lab there are pre-lab questions: 1. Describe the three general safety rules for working with a Bunsen burner.
Lab 1 – Introduction to Science Exercise 1: The Scientific Method Dissolved oxygen is oxygen that is trapped in a fluid, such as water. Since many living organisms require oxygen to survive, it is a necessary component of water systems such as streams, lakes, and rivers in order to support aquatic life. The dissolved oxygen is measured in units of parts per million (ppm). Examine the data in Table 4 showing the amount of dissolved oxygen present and the number of fish observed in the body of water the sample was taken from and then answer the questions below. QUESTIONS 1.
Answer = The dissolved oxygen (DO) is oxygen that is dissolved in water. The oxygen dissolve by diffusion by diffusion from the surrounding air aeration of water that has tumbled over falls and rapids and as waste product of photosynthesis, fish and aquatic animals cannot split oxygen from water (H2O) or other containing compounds. Only green plants and some bacteria can do that through photosynthesis and similar processes. (www.lenntech.com/why_the_oxygen_dissolved_is_important 3. Construct a hypothesis – Based on your observation in question 1 and your background research in question 2, develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of
Record your hypothesis on page 123. -My hypothesis is we can determine the different between each chemical reaction by the temperature change.To descide which one is exothermic and endothermic. 4. Summarize the procedures you will follow to test your hypothesis. -We measured in each chemical and added water besides, HCl we added NaOH.
As sucrose moves out of the phloem sap and into surrounding cells (with energy), water flows out of them. This reduces the pressure in the sieve cells at the sink region (less sugar) and the water moves back to the phloem Perform a firsthand investigation to demonstrate the effect of dissolved carbon dioxide on the pH of water 1. Blowing through a straw into the water 1. High technology read the levels of water pH as the carbon dioxide from our breath was dissolved into the water Perform a firsthand investigation using the light microscope and prepared slides to gather information to estimate the size of the red and white blood cells and draw scaled diagrams of each 2. Red blood cell = 7-9 um (micro metres) 3.
Pre Lab Objective: The purpose of this lab is to obtain the mass and volume of two different metal samples, to graph data, to obtain the slope of graphed data and to display a best fit curve of experimental data in order to graphically determine the density of each metal Background: Understanding the relationship that exists between a substance’s mass and its volume. This relationship is expressed by the physical property called density. (D = M/V). In order to determine the volume of solids, a technique called water displacement is used. A fixed amount of water is added to a graduated cylinder and the volume of water is recorded.
The salts will be dissolved in distilled water by small quantities until the reaction reaches When ionic compounds dissolve in water, they either absorb energy from or release energy to the surroundings. If a chemical reaction absorbs heat from the surroundings, it is an endothermic reaction. If a solution releases heat to its surroundings, it is an exothermic reaction. The enthalpy of dissolution is the enthalpy change associated with the dissolution of a substance in a solvent at a constant pressure. The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies.
Then allow test tubes to remain at various temperatures for 5minutes, remove the test tubes and add 2cm of catechol and shake to allow them mix. Finally the record the results. As temperature increases the rate of enzyme activity increases until it reaches its optimum point, in this graph the optimum point is 20-60 oC, This is the point where enzymes works best if temperature increases above the optimum point the rate of enzyme activity decreases until the point where the enzymes are denatured, the color intensity gets darker as temperature increases. Effects of pH on Enzyme Activity pH directly has an effect on the active site, and is therefore important to have proper pH,however high or lower ph. affect the enzyme activity, to get enzymes working there should be proper ph.