Initial Ph Test Lab Report

Purpose: The purpose of this experiment is to observe chemical changes in common consumer products to determine if the chemicals are basic, acidic, or remain neutral when mixed with other chemicals.

Add 5-10 drops of 0.1 M AgNo3 to each test tube. Add 10 drops of 6 m HNO3 to each test tube. Stir with a glass stirring rod. Any white solid that remains in AgCl(s). The color for unknown B was clean while the color of NaCl was a milky color, which mean Cl- was present.

Introduction: Blood pH is between 7.35 to 7.45. This range is strict, and those who have blood with a pH outside of the range are in danger of illness and death. In order for blood to maintain its pH within a one-tenth range, it uses a bicarbonate buffering system. The buffer resists pH change. Materials and Methods: For this lab, we titrated HCl into Na2CO3 while keeping a pH probe in the solution throughout the process.

The collected data does not reject the evidence. The data, however, also does not provide strong evidence for the hypothesis, instead showing that a significant deviance from neutral pH inhibits all enzyme action (the results of 2 ml each for the first and second experimental groups being attributed to human error). Therefore, the data simply shows the greatest reaction rate would have to lie between the pH’s of 4 and 13, as opposed to the hypothesis that the mixture would perform best near a neutral pH of 7.

The statement, the stronger acid has a higher pH than the weak acid , is proven to be false. pH is a measurement of the concentrations of hydrogen and hydroxide ions. To defined the pH we used the formula -log10[H+]. With this example H+= 1.0e^-2 equal the pH of 2 and H+=1.0e^-4 equal the pH of 4, we can see that the lower the pH values the concentration of hydrogen ions is higher when the pH goes up compare to when H+ decrease. HCl is a strong acid in which it completely ionize in water and become H+.

First, we started testing solutions such as Water, Sodium Phosphate (Buffer), and Sodium Chloride. The two control solutions that were used in experiment were HCl which is an acid and NaOH which is a base. The purpose of the two controls is to test and determine if NaCl is a buffer or not. When HCl was added to NaCl the pH decreased from 7.60 to 2.53 pH. The comparison of the pH change of NaCl and Na3PO4, shows that when adding acid to Na3PO4, pH did not change dramatically as it did with NaCl, only decreased from 9.30 pH to 8.73 pH. Comparing the pH changes of water and NaCl, the results seems that both have dramatic decrease in the pH level. The results shows that NaCl acted more as a water because when HCl was added, the pH dropped from

Step 3: I used a stir rod to determine if the mixed solutions are a precipitate or a non precipitate depending on what forms (liquid or solid) based on the mixture after all mixtures

The purpose of this experiment was to apply the understanding of basic solubility principles and precipitation reactions to identify two unknown cations in a given solution. The first two processes involved adding various acids and basis to the unknown solution to observe different precipitation reactions. The unknown solution contained either silver or lead and either barium or calcium. For unknown solution one, adding a sample of hydrochloric acid to the unknown solution started the experiment. This was imperative because it triggered a precipitation reaction, creating PbCl2 or AgCl. HCl was an ideal acid that was used because it was soluble to Calcium or Barium but atleast partially insoluble to Ag and Pb, allowing for the Calcium or Barium to have remained in solution, become isolated in a new test tube, and set aside for later use.1 The chloride ions are much more attractive to the silver and lead ions compared to the calcium or barium, which allowed some to precipitate while others to have remained in solution.2

The chronic administration of 0.75% (v/v) EG aqueous solution to the rats caused a significant increase in the urine volume (p < 0.001). On the day 30, urine output was 4.75 ± 0.35 ml/day in the control group, and 9 ± 1.21 ml/day in the EG group. HAEP increased further urine output when compared to the EG group during weeks 2nd, 3th and 4th week intervals and to the cystone group during 3th and 4th week intervals (Figure 1).

Amount of anhydrous salt by dividing the mass of the copper sulfide by the number of grams per mole, in 1 mole of copper sulfide: 0.01058mol

In this lab, the seeds in the pH of seven, pure water, grew the most out of both trials, just as predicted. In trial one, the radish seeds in pure water grew gradually over the period of six days, reaching the germination of 23 of the 25 seeds. However, all of the seeds in the other Petri dishes showed no growth over this course of time. Trial two mimicked about the same data, with 21 of the 25 seeds germinating in pure water and no growth in the other Petri dishes. The water in the Petri dishes that contained baking soda turned yellow and green in both trials, yet still showed no growth. At the end of the six days, the seeds in the Petri dish with a pH of seven began to turn green as the roots grew longer, resembling successful germination. Overall, these findings illustrate that seeds grow best in a pH of seven, pure water, thus proving the hypothesis

The aim of this experiment is to be able to identify the unknown solutions within the three different bottles. In this experiment a flame test and a solubility test were conducted in order to identify the unknown solutions. It is hypothesised that the flame test will be successful in identifying which cation (sodium, potassium and strontium) is in which solution through the colour of the flame. It is also predicted that the precipitate tests will successfully identify the anions (carbonate, sulphate and chloride) by testing the solubility of the solutions. The dependant variable is the chemicals in the unknown solutions. The independent variable is the flame test and precipitate test and the controlled variable is the unknown solutions which are tested.

To begin the experiment and start the process of narrowing down the list of twenty-five compounds, a Tollens’ test was performed on the chosen unknown (Unknown #6). In a test tube, 1 mL of 0.3 M AgNO3 was added along with 0.5 mL of 3 M NaOH. To that, 2 M NH4OH was added dropwise until the brown silver oxide precipitate dissolved. After, one drop of the unknown was introduced to the mixture, the tube was shaken and left to sit at room temperature for ten minutes. The predicted silver mirror coloration did not appear indicating a negative test result.

Water is a chemical substance of which is scientifically called H2o. This means that each of the molecules contains one oxygen and two hydrogens. In the experiment the water was solidified into ice cubes and therefore the experiment was a physical change, due to the substance not changing when the ice melted. There were no chemicals added into the experiment therefore it was not a chemical change the water molecules were still water molecules. When heat is added to a substance the molecules vibrate faster, and as they move faster the space between the molecules increases, eventually causing the substance to turn into a gas if heated long enough.

pH levels effect on Enzyme Activity and Concentration Abstract: pH level may affect enzyme activity and the performance of the enzyme which is crucial in order for the enzyme to properly function in our biological systems. We investigated the relationship between pH level and rate of enzyme function at that certain pH level. The enzyme concentration was recorded at varying levels of pH using the enzyme Lactase, substrate ONPG, and phosphate buffer in a spectrophotometer set at wavelength 405nm. As pH levels became extremely high or low, enzyme concentration decreased.