Temperature Change Lab Report

In cycle one, the double displacement reaction, Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) occurred, the result of the reaction was that the reaction mixture began to bubble with the copper filling dissolving and a vapor like substance leaving the reaction. Furthermore, when water was added, the color change, from brown to a blue color pigment. Then in Cycle two, another double displacement reaction occurred, Cu(NO3)2(aq) + 2NaOH(aq) → Cu(OH)2(s) + 2NaNO3(aq), which resulted in the reaction becoming cloudy and a darker shade of blue. Following cycle two, a decomposition reaction occurred as the result of heat being administered to the mixture, thus the following reaction occurred in cycle three, Cu(OH)2(s) → CuO(s) + H2O(l). As a

1. A number of different items were measured in this lab. For each of the following items, what did you find most challenging in making the measurement and how did that challenge affect the accuracy of the measurement? a) Length of the table b) Height of your partner c) Thickness of your finger

For Sprite trial 1, for the green part of the liquid, it went from clear to green. Then for the Sprite trial 2, it started at green and went to whitish green and ended with yellow. Then in Sprite trial 3, it went from green to a darker green and then to a light green. Then for the green gobstopper in Sprite trial 1, it started at green and then became a whitish green and ended with a white. Then for the Sprite trial 2 it began with green, then went to a yellow, to whitish yellow, back to yellow, to yellowish green, and finally ended with yellow.

They tested how the temperature would affect the rate of reaction. This was observed by the amount of time it took for the solution to change colors. For many chemical reactions there is an optimum temperature at which the chemicals will react with each other. As was found in their experiment, the temperature affected the rate of reaction. (Deoudes, 2010).

These color changes indicate a chemical change, which show that a reaction had occurred. In the first step when o-vanillin and p-toludine, imine was formed. The color change from green to orange suggests that imine appears as orange colored. In the second step, the addition of sodium borohydride reduced the imine into another derivative, which was yellowish lime color. The solution turned clear when acids and anhydrides was added, which indicated the precipitate were dissolved.

The observed emission data for the different elements did not look how they were supposed to. However the “peaks” for Hydrogen were found to be 534.52 and 631.24, 534.70 and 569.11 for Helium and 529.73 and 630.71 for Mercury. The Rydberg’s Constant found to 1.1x107 8.5x104 while the known constant is 10967758.34m-1. The percent error of 0.29% and the accuracy of this reading is 99.7. The slope and intercept of the linear regression line is -0.01 3.3x10-5 and 0.02x10-1 1.9x10-6 respectfully.

the pH has changed a little more since the sand is present, so the change in color is

The percent recovery of the copper was calculated using the equation, percent recovery = (the mass of the copper recovered after all the chemical reactions/the initial mass of the copper) x 100. The amount of copper that was recovered was 0.32 grams and the initial mass of the copper was 0.46 grams. Using the equation, (0.32 grams/0.46 grams) x 100 equaled 69.56%. The amount of copper recovered was slightly over two-thirds of the initial amount.

The next test used the test tubes labelled “cold” and , one again using a piece of liver and five milliliters of hydrogen peroxide with both being placed in the ice bath, both held vertical with a test tube clamp. After five minutes were up using a timer, the two tests were conducted. The test involving the boiling water had five milliliters of hydrogen peroxide poured into it. Meanwhile, the five milliliters of hydrogen peroxide was poured into the test tube labelled “cold”. After both tests, explanations were made about the

The solution of DCM and cyclohexane was clear and colourless. The following graph shows the recorded

Research question What is the effect of temperature Amylase activity? Word count-1453 Background research Enzymes are biological catalysts that speed up a chemical reactions. They do this by decreasing the activation energy(the energy needed to start the reaction) of a chemical reaction. The enzyme present in our saliva is called Amylase. Amylase increases the rate of reaction by decreasing the activation energy needed to hydrolyse the starch molecules.

As you can see from the pictures the purpose of this lab was to show the change in shadow length at various times of the year with a given object/location. According to my research, the change in the shadow occurs in part because of the change in season. Seasons are caused by earth’s orbit and titled axis. The tilt of the earth on its axis changes the seasons. Also, the gradual change in the length of your shadow over the course of the day is caused by the various positions of the sun.

Effect of Yeast on Temperature on Hydrogen Peroxide Solution in Water Khalid Al Sabeeh Ms. Dobrin 11-G Chemistry HL Jan 5, 2015 Abstract: Within this lab yeast was added to hydrogen peroxide solution in water. Temperature was the factor to be tested. In all trials, the initial and final, when yeast was added temperatures increased by 10˚C respectfully per trial.

Through the titration process, we are able to identify physical changes to the mixture such as the colour change to indicate the end point of the experiment. For example, the colour changes of phenolphthalein from colourless to pink and methyl orange from red to orange and subsequently yellow. Acids produce hydrogen ions and bases produce hydroxide ions. This causes the indicator to change colour due to the colour difference from the undissociate molecules.

The solution with the pigments was spotted 15 times on both region A and region B and then allowed to dry. When the plate was dry it was placed into the tank for at least 20