Water & Solutions End of Unit Project By: Shelby Stewart & Brigitte Harris

Lab Report Here is the link to the Lab Report for the Water and Solution End of Unit Project: 7P4aHVac8u-ctlhCogsEJY/edit?usp=sharing Math ComponentMath Component (click)

Pictures! Lab Partners Our Elephant Toothpaste!

More Pictures!

How does it work? Foam is awesome! The foam you made is special because each tiny foam bubble is filled with oxygen. The yeast acted as a catalyst (a helper) to remove the oxygen from the hydrogen peroxide. Since this occurred very quickly, it created lots and lots of bubbles. This reaction is an exothermic reaction. Not only did this reaction create foam, it also created heat!

Solute & Solvent The solvent in this experiment is the hydrogen peroxide. The solutes in the Elephant Toothpaste was the yeast and Dawn dish soap.

Balanced Chemical Equation The overall equation for this reaction is: H2O2(aq) + I-(aq) → OI-(aq) + H2O(l) Net Ionic Equation: 2 H 2 O 2 (aq) → 2 H 2 O(l) + O 2 (g) This reaction is a decomposition reaction which decomposes the hydrogen peroxide into water and oxygen (in the bubbles).

Precipitation Reaction A precipitation reaction is a chemical reaction in solution chemistry. Two or more substances are combined and produce a precipitate. Typically, these types of reactions involve ionic compounds in an aqueous solution. This experiment qualifies as a precipitation reaction because the decomposition of the hydrogen peroxide into water and oxygen is catalyzed by the iodide ion.

Types of Reactions ❖ An acid-base reaction is a chemical process demonstrated by the exchange of one or more hydrogen ions, H+, between substances that may be neutral or electrically charged. ❖ A neutralization reaction is a reaction of an acid with a base to produce a salt and water. Since acids and bases cancel out each other's properties when the combine, the aqueous salt solution created will be neither slippery nor reactive with metals.

Types of Reactions (continued) ❖ Titration is the slow addition of one solution of a known concentration (called a titrant) to a known volume of another solution of unknown concentration until the reaction reaches neutralization, which is often indicated by a color change. The solution called the titrant must satisfy the necessary requirements to be a primary or secondary standard. In a broad sense, titration is a technique to determine the concentration of an unknown solution.

Properties of The Solution There are many types of reactions that take place in this experiment. The first reaction is a decomposition reaction. The hydrogen peroxide decomposes into water and oxygen. The second reaction is an exothermic reaction. An exothermic reaction is when energy is released in a reaction, causing heat. The third reaction that occurred in this lab was a neutralization reaction. In the beginning of this experiment, it started out with hydrogen peroxide, which has a pH of 4.0. After the reaction took place, the substance turned into water and soapy bubbles (from the Dawn dish soap). Water has a pH of 7.0, which is neutral.

Math Component - Data Table Time (seconds)Volume (in 3 ) (2 minutes and 30 seconds) (When the reaction calmed down) 179 Volumes of the Elephant Toothpaste at various times:

Growth of The Elephant Toothpaste The volume of the Elephant Toothpaste started out growing very rapidly. The entire 2L soda bottle was completely filled with Elephant Toothpaste just after 30 seconds. After a few minutes, the volume continued to grow, but not as rapidly. Originally, this experiment would take a very long time to complete. The catalyst, the yeast, helps speed up the reaction.

Logarithmic Growth A Logarithmic Growth is the inverse of an exponential growth and is very slow. Logarithmic phenomena grow very slowly, and have an equation of the form y = log b x. Our Elephant Toothpaste growth is similar to logarithmic growth in the sense that without the yeast catalyst, it would take a long time for this reaction to take place.

Our Graph This graph shows our calculated volumes (blue points) vs our logarithmic equation (red line). Volume (in 3 ) Time (seconds)

Our Equation Our equation is: y = 30log 2 ( x+3) There were a couple transformations applied to this graph. The first transformation that was applied to the parent function, y=log(x), is a vertical stretch. The vertical stretch in the equation is 30. This stretched the equation vertically by 30 units. The second transformation that was applied is a horizontal translation. The horizontal translation is the +3. This translated the graph 3 units to the left. The third and final transformation that was applied to the parent function, y=log(x), is a vertical translation. The vertical translation was This translated the graph down units.

30, 60, and 90 seconds 30 seconds: Equation: y = 30log 2 (x+3) y=30log 2 (30+3) y=111 The calculated volume of the Elephant Toothpaste after 30 seconds is 111 in seconds: Equation: y = 30log 2 (x+3) y=30log 2 (60+3) y=139 The calculated volume of the Elephant Toothpaste after 60 seconds is 139 in seconds: Equation: y = 30log 2 (x+3) y=30log 2 (90+3) y=156 The calculated volume of the Elephant Toothpaste after 90 seconds is 156 in 3.

Final Data Table Time (seconds) Volume (in 3 ) 30 calculated calculated calculated (2 minutes and 30 seconds) (When the reaction calmed down) 179 Time (seconds) Volume (in 3 ) Volumes of the Elephant Toothpaste at various times:

Final Graph Link to graph on Desmos: 1ejmazh 1ejmazh This graph shows our volumes (blue points) vs our logarithmic equation (red line) vs our calculated volumes (orange points). Volume (in 3 ) Time (seconds)

Bibliography ●Bell, Ronald Percy. "Acid-base Reaction | Chemistry." Encyclopedia Britannica Online. Encyclopedia Britannica, 10 Feb Web. 12 May base-reaction ●Helmenstine, Ph.D. Anne Marie. "Elephant Toothpaste Chemistry Demonstration." About Education. About.com, 2 Dec Web. 12 May ●"Linear v. Polynomial v. Exponential v. Logarithmic growth - Comparisons - Knewance Difference Engine." Knewance Difference Engine. Knewance, 15 Apr Web. 13 May ●“The Elephant's Toothpaste Experiment - ScienceBob.com." ScienceBob.com. N.p., 26 July Web. 12 May ●"Titration." - Chemwiki. N.p., n.d. Web. 12 May ●"What Is the PH of H2O2 Solutions?" U.S. Peroxide. U.S. Peroxide, LLC, 21 Oct Web. 13 May