Quynh+Anh+&+Tuan+Anh

10 – 12 – 09 
 * LAB: Some Metals Are More Reactive than Others **


 * B. ** **__Aim:__** To test, compare and rank the reactivity of iron, aluminum, copper, magnesium, and zinc with hydrochloric acid from most reactive to least reactive.

 || Amount of sample metals || One spoonful of powdered metal will be used. The same scoop will be used to provide accuracy. || If iron, aluminum, copper, magnesium, and zinc were all put into hydrochloric acid, then the most reactive element would be magnesium, followed by aluminum, zinc, copper, and iron because magnesium creates an ion of 2+, aluminum creates 3+, zinc creates 6-, copper creates 8-, and iron creates 8+ and the closer an atom is to having a full valence shell, the more reactive it is.
 * C. ** **__Variables Table:__**
 * **Variables ** || **What is changed/ measured/ controlled? ** || **How is it changed/ measured/ controlled? ** ||
 * **Independent ** || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Types of metals || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Use five different types of powdered metals for this experiment; iron, aluminum, copper, magnesium and zinc. ||
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Dependent ** || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">The reactivity of the metals when immersed in hydrochloric acid. || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Observe and judge the size of the balloon used to cover the mouth of the test tube containing one type of metal in hydrochloric acid. When any type of metal is put in acid, hydrogen will be given off. The balloon will expand due to this. Hence, the more the balloon expands, the more reactive it is. ||
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Constant **
 * ^  || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Amount of time the balloon is kept on the test tube and observed. || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">The experiments will all be filmed. Use the time on the camera to make sure that the balloon is observed for 2 minutes. ||
 * ^  || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Amount of hydrochloric acid. || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">A graduated cylinder will be used to make sure that 10 ml of hydrochloric acid is used. ||
 * ^  || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Other equipments and materials (test tube, balloons) || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">The same size and type of test tubes and balloons will be used for all experiments. ||
 * D. __Hypothesis:__ **


 * E. __Equipments and Materials:__**

- 5 test tubes - 5 balloons - 1 stop watch - 50 ml of hydrochloric acid - 1 camera - 1 small glass spoon - 1 stop watch - 1 scoop of magnesium, aluminum, zinc, copper, and iron - 1 test tube rack

<span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">1. Get all the equipment needed. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">2. Measure 10 ml of hydrochloric acid using the graduated cylinder. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">3. Poor the hydrochloric acid in a test tube. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">4. Place the test tube on the test tube rack. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">5. Start recording the experiment using the camera. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">6. Put one scoop of magnesium in the test tube. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">7. Quickly cover the mouth of the test tube with a balloon. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">8. Wait and observe the experiment for 2 minutes. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">9. S top recording the experiment. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">10. Record any observations necessary. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">11. Remove the balloon. <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">12. Repeat steps 2 to 10 with the other types of metal (iron, copper, aluminum, zinc).
 * F. __Method:__**


 * G. __Diagram of apparatus:__ **

<span style="font-size: 12pt; mso-bidi-font-family: Arial; mso-bidi-font-weight: bold; mso-fareast-font-family: 'Times New Roman';">Table of qualitative observations of what happens when one small spoonful of powdered metals including; magnesium, iron, copper, aluminum, and zinc is immersed in 10 ml of hydrochloric acid - There is a large amount of bubbles floating up in the acid - There is some condensation on the test tube - The liquid is translucent - The balloon inflates quickly and is quite big || - Many small bubbles can be seen - The liquid is translucent - The balloon is slightly inflates || - The liquid stays clear - The balloon stays deflated || - Liquid is clear - There are no bubbles - The balloon seems to stay the way it was before the experiment || - The powder slowly sinks - The liquid becomes clear - There are some bubbles - It can’t be seen, but when touched, a small amount of air can be felt in the balloon || Order of reactivity between the five metals; <span style="font-size: 12pt; mso-bidi-font-family: Arial; mso-bidi-font-weight: bold; mso-fareast-font-family: 'Times New Roman';">magnesium, iron, copper, aluminum, and zinc when immersed into hydrochloric acid according to the results from the experiment
 * H. __Observation table:__**
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Type of metal **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> || **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Qualitative observations **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> ||
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Magnesium **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">- The magnesium sank to the bottom of the test tube
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Iron **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">- The iron powder sank to the bottom of the test tube
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Copper **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">- Some of the powder sank to the bottom of the test tube while others stayed floating on the liquids surface
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Aluminum **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">- The powder stays floating on the surface of the liquid
 * **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Zinc **<span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">- The zinc powder spreads around in the test tube
 * I. __Processing and presenting data:__ **

<span style="font-size: 12pt; line-height: 115%; mso-bidi-font-family: Arial; mso-bidi-font-weight: bold; mso-fareast-font-family: 'Times New Roman';">1. Magnesium 2. Iron 3. Zinc <span style="font-size: 12pt; mso-bidi-font-family: Arial; mso-bidi-font-weight: bold; mso-fareast-font-family: 'Times New Roman';">4. Copper

4. Aluminum <span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">1. <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Answer your aim:
 * J. __Conclusion:__ **

According to the results of the experiments done in this lab, out of the five metals, magnesium is the most reactive with hydrochloric acid followed by iron, zinc, and the two least reactive metals; copper and aluminum.

<span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">2. <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Do the results support the hypothesis?

The results do not support the hypothesis. The hypothesis predicted that magnesium would be the most reactive to hydrochloric acid because it is has the smallest ion, in other words, closest to being a noble gas. The results supported this; however, the order of reactivity predicted in the hypothesis is completely different to the actual results after that. The hypothesis predicted that after magnesium, aluminum would be most reactive, followed by zinc, copper, and iron, while the results shows that iron is the second most reactive, followed by zinc, then copper and aluminum at a tie for least reactive. This must mean that the hypothesis is not correct. There is most presumably, another factor besides ions which affects the reactivity of these metals, or that this experiment is not valid and reliable. <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">

<span style="font-size: 12pt; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">3. <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';">Where possible, compare the results to published data and/or theories.

2. Aluminum 3. Zinc 4. Iron 5. Copper || <span style="font-size: 12pt; mso-bidi-font-family: Arial; mso-bidi-font-weight: bold; mso-fareast-font-family: 'Times New Roman';">1. Magnesium 2. Iron 3. Zinc 4. Copper/Aluminum || <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> Out of magnesium, iron, zinc, copper, and aluminum, magnesium was the most reactive in our experiment. When compared to other published data or theories, magnesium is shown as the most reactive to hydrochloric acid out of the five metals in general too ("The Reactivity Series"). I t is also shown that aluminium the second most reactive element out of those 5. However during the experiment, aluminium showed the least reactivity to hydrochloric acid. There are also many other differences between the ranking of reactivity according the results of the experiment and the ranking on “The Reactivity Series” article as can be seen in the table above. And because of the fact that the published data does not match with the one recorded in this experiment, the experiment might not have been reliable and the data collected might not be correct. <span style="font-size: 12pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman';"> <span style="color: #333333; font-size: 12pt; mso-ansi-language: EN-GB; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin; msoansilanguage: EN-GB; msobidifontfamily: Calibri; msobidithemefont: minor-latin; msolist: Ignore;">4. Explain the conclusion scientifically.
 * <span style="font-size: 12pt; mso-bidi-font-family: Arial; mso-bidi-font-weight: bold; mso-fareast-font-family: 'Times New Roman';">Published data || Results ||
 * 1. Magnesium

The reactivity of the metals depends on how close they are in becoming a stable octet. The closer they are to becoming a stable octet, the more they'll react to hydrochloric acid. This is because every element besides the noble gases wants to have full outer shells. In this case, magnesium was the closest to having a octet shell because it just need to lose two electrons to become a stable octet while all the other metals that we tested needs to lose/gain a larger amount of electrons in order to have full outer shells. This is why certain elements are more reactive than other elements and why magnesium would be more reactive to hydrochloric acid than aluminum, iron, zinc, copper. This rule works for all the other four metals, except for aluminum. It was appeared the least reactive in this experiment. However, according to published theories, aluminum is supposed to be the second most reactive. This could mean something went wrong in the experiment. More experiments focusing on aluminum is needed to be done to find the reason why this pattern does not work for this metal. 1. Reliability: The data collected through this experiment is not very reliable because there was only one trial done, making the result less accurate.
 * K. __Evaluation:__ **

2. Validity: In this experiment, the correct variables and constants were chosen so that the result could be as accurate as possible. However some variables could not have been controlled totally. An example is the amount of metal used. Different metals have different density volume, and weight so it is very hard to have an exact same amount of powdered metal for each experiments. Along with that, there were also some faults in the method. The time was measured using the camera instead of a stop watch. However, the time it takes to put the sample metal in the test tube and cover it with a balloon would be different for each experiment, making the time the balloon is observed for different as well. Because of all those factors, this experiment cannot be considered 100% valid.

3. Table of weaknesses and improvements:

4. What made this a fair test? This experiment was not a fair test. There was meant to be one independent variable, but there were some other small independent variables as well due to the fact that the constants were not very well controlled. These other independent variables created were mentioned in the weaknesses and improvements table above, and they are also the factor making this an un-fair test.
 * ** Weaknesses ** || ** Improvements ** ||
 * A stop watch was not used to time the experiment, instead the camera was used. The problem with this, though, is that it takes some time to put the powder metal in the test tube and the cover it with a balloon. It would take a different amount of time to do this for each small experiment. This means that the amount of time the balloon was observed for did not stay the same for each small experiment. This could have affected the results because some small experiments had more time for the hydrogen to be released from the hydrochloric acid. || Next time, a stop watch should be used to time the experiment. It should be started right after the balloon is put over the mouth of the test tube to insure that the amount of time the balloon is observed for is the same for all of the small experiments. ||
 * Not all of the metal powder made it into the acid in the test tube. A lot of it got stuck on the sides of the test tube as well. This would mean that the amount of metal powder that was used for each experiment is different. || Next time, a very long and thin spoon should be used. One should stick the spoon into the test tube until about 1 cm away from the acid level, and then drop the sample powder metal. This would prevent the metal powder to be stuck on the wall of the test tube. ||
 * The sizes of the metal powder grains are different. || Next time, the metal powder used should all have a relatively same size, as this could affect the result of the experiment. ||

"The Reactivity Series of Metals." //TutorVista.com//. N.p., 2008. Web. 17 Dec. 2009. <http://www.tutorvista.com/content/science/science-ii/ metals-non-metals/reconcept-series-metals.php>.
 * __ Bibliography: __**