Lab 10.2: Solubility vs. Temperature

Our graph was similar to table G in our reference tables but because we only had four points our graph it showed some differences and created some room for error. Only using ten grams of solvent instead of one-hundred on our graph created less accurate results as compared to the one on table G.
In our experiment the temperature of water impacted on how quickly solvent dissolved. The more KLO3 (greater concentration) the more time it takes to dissolve. To dissolve more quickly we put the test tube into a hot water bath to increasing the temperature of the solution. When the solution is liquifyied the particles make more collisions, and they are also more efficient(effective). At the liquid stage the particles are less attracted to each other than at a solid. bB crushing the KLO3 you could increase its surface area and help to speed up the rate of reaction. In our experiment the solution was unsaturated when the KLO3 was undissolved at the bottom of the test tube. It was saturated when the KLO3 had completely dissolved into the solution.

Enrichment:
Rock candy is a saturated solution. Yo saturate the water you add as much sugar as it can take, but then heating the water you create more space for sugar creating a supersaturated solution. You would then add the string into the water on which the rock candy would form as the water cools the sugar to come out of the solution forming a precipitate which we know as the crystals of the rock candy. This is because the super saturated solution has more sugar in it than it can possibly hold.

Lab 11.1: Corrosion of metals

1.
a) The penny wrapped in steel wool was less corroded then the unwrapped penny.
b) This is sacrificing metal technique because you did not coat the penny with a metal so only the outside only corrodes you merely wrapped it leaving some parts of the penny showing and corroding. The iron was "sacrificed" so most of the penny was protected(steel wool was corroded in place for the copper in the penny).
c) This works because iron is more active on table j than copper so the copper won't react with the rain. The active iron bands react with the rain and become erroded but leaves the copper unharmed. Hence them being checked and replaced regularly.
2.The corrosion is occuring because the aluminum is more active than the iron that was surrounding it; yhe Al ion and the iron are reacting because the metal is higher on table j.

3. The caulk would've created a barrier between the Al and Fe. So there would have been a coating and less corrosion would have had taken place.

4.
a) Corrosion is when a metal and an ion reacting cause the metal to errode.
b) Chemists have created different ways to outsmart it by putting the iron is the copper made statue of liberty or using caulk between the metals and ions. This coats the metal they want to protect with another metal so that metal will corrode instead of the one you need.
Enrichment:
Al+O2---> Al+3 and Fe +Al+3 ---->Al +Fe +3.
Aluminum is represented by A and iron would represented B.

Lab 11.2: Table J and Metal Reactivity

1.    a) The nitrate ion known as a “spectator ion” is an appropriet title because as examined in the reaction equation nitrate stays the same befor and after the reaction. 

     b) In the reaction between magnesium and silver solution, silver was oxidized and magnesium is reduced. 

2. Metal X and metal ion Y⁺² will react, when X is higher then Y based on Table J.

3.  1. An activity series is a list of substances ranked in order of decreasing relative reactivity. The most metallic elements of group 1 have the most relitive reactivity nonmetalic elements at the bottom of table J are the least reactive(left side of table s moving towards the right go from most metallic elements to non metallic).

     2.   Which ever metal is higher on table J is more reactive then the metal below it.

4. Gold, silver, and copper are on the bottom of table j suggesting the are the least reactive metals. This made it easier for humans to discover these metals because they havent reacted with there surrondings. Other metals (lead, tin, iron, mercury) that are more reactive were dicovered much later because you must go deeper into the surface to find these metals nonreactive to the surrondings.5. 

• Copper was smelted from its ores Malachite and Azurite in anctient times. In a pottery kiln with charcoal these elements were fired and reduced to metallic copper.
• Bronze is made of copper and tin melted together at high temperatures.

Enrichment:

The light sensitivity of the silver halides exposed to a light, a chemical reaction darkens the film to produce an image. AgCl used in photography, consists tightly packed ions of silver and chlorine, when film containing Ag+ and Cl- is exposed to light energy, the chlorine ion's extra electron captured by a silver ion. When silver metal is produced as a result of the electron capture, it forms a dark image on film.  Ag+ has been reduced to Ag (metal), and Cl- has been oxidised.

Lab 10.3: Titration+ Colligative Properties

• When measuring the concentration of base (NaOH) there was not much difference in the readings of each sample. This wasnt surprising since we were doing the same procedure with the same material three times.Some possible errors that may have caused differences in the values are not reading the graduated cilinder to an exact decimal amount or not reading the value at the exact time of post-neutralization (8 pH). To fix this you can have more then one person observe at the same time as you to catch the right value right at nuetralization and also have a graduated cylinder with more measurement marks for a more precise measure rather then geuss the value between two lines.
• Antifreeze is an important for your engine in different climates. When the temperature gets cold we need something that has a lower freezing points to still finction in cold weather. Antifreeze has chemicals that will remove the access metal and other substances from your car engine, without freezing in the pipes of the engine. By having molecules that can be dissolved into ions and are soluble in water in the antifreeze, the freezing point is lowered because of the energy transfers. In order for water to freeze, a set ratio of water molecules needs to form a specific crystal  If extra ions are in the water, the polar ends of water molecules will attract to these ions more so than they will with other water molecules. Therefor the antifreeze will not freeze the pipes within your car while in use. The opposite happens when it is really hot out. When the temp may be above the boiling point of water the extra ions increase the boiling point because the attractions are stronger than standerd hydrogen bonds between water molecules. So with stronger bonds between molecules, the more energy will be need to break them apart meaning a higher boiling point. Antifreeze is needed in order to raise the boiling point of the water above the temperature surronding it so that the water solution created stays a liquid and allows your car to function.
  
• Enrichment: Ice cream.
  The dissolved sugar, by getting in the way of the molecules that bond together to form ice crystals lowering the freezing point of the cream. This is why the cream solution will not freeze at the same temperature that water freezes. When the temperature of the cream gets low enough the water molecules have slowed down enough thso now their attraction becomes stronger than the disruptive influence of the sugar. For the temperature of the cream to get low enough  they crystallize, the water molecules are removed from the solution which means the remaining solution gets more concentrated with sugar so its freezing point is even lowered further.

Lab 10.1: Solvents (Like Disolves Like)

1. Salt and sugar are definitely polar because they have a strong attraction to the polar water(like dissolve like).The samples with the other solvents are non polar and since the polarity is unalike they do not dissolve in the solution.
2. Vegetable oil is definitely non polar because they have a strong attraction to the non polar hexane(like dissolve like).The samples with the other solvents are polar and since the polarity is unalike they do not dissolve in the solution.
3. Ethanol has a polar and non polar end since it only can slight dissolve both non polar and polar solutes.
4. Ethanol could dissolve in both water and hexane since it has a polar and non polar side of the molecule it allows it to dissolve with polar water and the non polar side of hexane. This makes the solution slightly soluble as only one side of the molecule can be dissolved with like side of the molecules polarity matching the solvent.
5.  

	Type of Molecule	Solubility in Water	Solubility in Hexane
NH3	Polar	Soluble	Insoluble
I2	Non polar	Insoluble	Soluble
HCl	Non polar	Insoluble	Soluble

• 6. Ionic materials dissolve well in water because they are both polar. Hexane is non polar, solutes dissolve in other solvents of the same polarity as themselves.

Enrichment:

Nitrogen, oxygen, and carbon monoxide are all non polar so they do not dissolve in the polar water, like dissolve like. Oxygen is produced for fish by the plants who use carbon and carbon dioxide is stored in water these ions are an important part of natural buffers that prevent the water from becoming too acidic or too basic for aquatic life to live it.

Blog 9.2: LeChatelier's Principle

When HCL is added to the system the system shifted to the right to balance out the HCL indicted by the dark blue color change this means concentration of Cl- ion increased.

1. Since the system is exothermic when heated the heat is added to the reactant side of the system. This causes the system to shift to the right (indicated by dark blue color).
2. If the reaction is endothermic the reaction has more potential energy on the reactant side of the system. This means the heat of reaction has a positive sign because it is storing(gaining) energy. If the reaction is exothermic the potential energy decreases because it is being released in the form of heat this is shown on the product side of the system. This means the heat of reaction is negative because it i loosing energy.
3. Ag+ and Cl- when but together do not create a soluble compound according to table f. This was shown in the lab when mixing the silver with chlorine you are left with a cloud showing in the mixture showing they are creating a new compound and not mixing together. The solution around it was light pink this indicates a shift to the left decreasing Cl- to balance out the system.

Station 3 question:

1. When increasing pressure the gas bubbles in the soda go away to put the solution in equilibrium. When you decrease pressure you give more space for air bubbles to form to shift the system back into equilibrium. This is the same as when you open a soda you are decreasing the pressure of the soda inside the can so the formations of bubbles to balance out the can cause it to "effervesce" (release gas).

Enrichement:

1. Chickens pant out CO2 gas.
2. When the CO2 decreases the equilibrium of the system shifts to the right.
3. When the system shifts right it causes a decrease in the amount of CaCO3 (egg shell) produced by the chicken.
4. The panting resulting in thinner egg shells because as a result of having less CaCO3 produces less egg shell for the eggs this means the eggs have to have a thinner shell.
5. To insure their chicken produce normally think egg shells in warm weather farmer could air condition the chicken coupe. This takes advantage of Le Chatelier's Principle by manipulating the temperature of a system to achieve the results you want.

Lab 9.1: Heat of Solution (Delta H)

1. In the solution of Ammonium Nitrate(NH4NO3) and water (H2O) the process that occurred was endothermic. The direction of heat flow was pointed into the solution absorbed by the process making the system and its surroundings a chilled temperature.

2. Error may have been from the rounding of the decimal place used by the thermometer when calculating the solutions temperature. Also we could not calculate for the heat absourbed by the sides of the cup and the thermometer.

3.A.)If the room temperature was ten degrees colder the total heat would have been different  and less energy would be used for the change in temperature (smaller delta H)because the change in solution was endothermic the temperature is already decreasing.

B.)If you added less chemical but you still knew how much you add, the q value and the moles of solute would be lower (lower concentration) but because they are going to proportionally lower the reaction is smaller causing a smaller change in heat (Delta H).

C.)If you added 40mL of water but thought you had 50 mL the change in heat would appear to be less because you have less water to change the temperature of the reaction. Less water equals a smaller change in temperature. 

Enrichment:   In Florida farmers spray their trees with water to protect the trees from being damaged. This helps the trees when the weather gets cold in order to preserve the tree and keep it healthy for the farmer. When something freezes (mist sprayed) it creates an exothermic reaction, this causes the realease of heat. As the heat is realeased it prevents the trees from freezing throughout the cold weather.