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.

Lab 8.2:Hydrocarbon Properties

When the particle attractions are stronger, the molecular size of the particle is larger. This effects properties like boiling point. When the attractions are stronger the size of the molecule increases creating more viscosity. This means they'll be hard to take apart because there bonds are stronger. It will take more energy to break these stronger bonds so the boiling point is increased. When the particle attraction is lower so is the boiling point because it takes less energy to break the bond creating less viscosity.

Enrichment:

Before the oil can come out of the ground it has to be found.Geologists look at surface rock and soil types to determine where the oil might be located. Modern oil geologists examine surface rocks and terrain, with the addition of satellite images or locate oil using Vibrator or Thumper trucks to cause vibrations in the earth which are listened to by geophones. The data is processed by computers into dimensional displays that are seismic lines.

When it is time to dig into the ground for the oil, the land has to be flat and cleared. After the well has been drilled, a measuring device is lowered into the hole and information is gathered about the properties of the earth such as density, type of rock present, and what fluids the rocks may contain.The drill used requires water, so there has to be a water source. A reserve pit is dug to put the rock and mud that come up with the drilling. Now they drill many hole to place the rig and support the main drill.

When they are ready to drill, they set the drill tip in the hole and begin drilling. They add and remove pieces of the drill as it goes deeper. When the drilling is over a cement pipe goes down the hole then allow the oil to flow. Then they build a cement well directing the oil  into the well. The pump they place into the well that sucks out the oil.

Lab 8.1: Percent compositon

Some source of error in the experiment may be from when chewing the gum. When chewing the gum you may be consuming not only the sugar but fragments of the gum of itself this may make your measurement for sugar higher, since more weight is missing from the gum. Another source of error in this experiment could be how long you  chew the gum before all of the sugar is dissolved. A person might think that all the sweetness is gone, and they weigh the gum, when really, some sugar is still may be left this would make the measurement for sugar less. The percentages of sugar is effected by this error becoming a higher percentage of sugar with more weight lost and a lower percentage of sugar with less weight loss.

Enrichment: Blogs help us look back on what we did in class sometimes clarifying the information we learned or review it and sometimes the assignment may be easy and quick. Gaining access to a computer may be not accessible to every student some may also like writing better then typing. Lastly enrichment i find is the most time consuming at times and least helpful. I find it sometimes unnecessary it may be more useful if it connected our chemistry topic to our everyday lives. Not enriching us further about other chemistry experiments hard to understand and not necessarily needed to be informed of.

Lab 7.4: Reactivity of metals

1 and 2. Elements that are in the same group have more similarities than elements in the same period. Elements with the same number of valence electrons and similar properties are most similar. These similar elements share the same characteristics and reaction times.This can be proved from the data we collected when metals were being place into water and phenolphthalein.When the data was collected the six elements could be easily placed in three different groups based on properties observed.Group 1 (Na, K, and Li), properties for this group were started with each containing one valence electron then observing that the element reacted fast with the air, the elements floated in water, an exothermic reaction,and the water (phenolphthalein turned pink) meaning that the element is basic. Knowing these similarity's it can be concluded that all of these elements are in Group 1.The elements in our group 2 (Mg and Ca) also shared many identical properties and both had valance electrons of 2. And finally, the group left had only contained the element Al. Al had different properties than all the other elements, also had a different valance electron valance electron of 3.

 

3.When an element of sodium reacts with an non-metal:

a) the sodium atom will want to lose1 electron(metals loses electron) so that it can get to a stable octet.

b) the sodium ion will become positive ion called a cation. This is caused by loosing an electron there is one more proton, making it positive.

c) 1+

d) Its new electron configuration would be 2-8 that of Neon

e) The sodium ion will be more stable because it has 8 valance electrons resulting in a stable octet. 

Enrichment:

Alkali metals almost always form ions with a positive charge of +1, and are so reactive as elements that virtually all occur in nature only in compound form. Sodium a highly reactive element is in its pure form reacts with elements and moisture in the air almost immediately. It is more stable in compounds, so this is how it is found in nature.Pure sodium metal can be prepared by the process involves the electrolysis of NaCl mixed with proper amount of CaCl₂ to lower the melting point of NaCl. this process produces up to 99% pure sodium metal

7-2 Atomic mass of Pennium.

Pennies were good as isotopes because depending on the generation pre or post 1982 the penny contains a different ratio of zinc and copper.The new generation penny with less copper can be considered an isotope of pre 1982 penny's almost made of pure copper. A problem that can occur using penny's as an isotope is that they don't have a constant (like atomic number) like real elements and their isotopes.
1.The atomic mass is 35.45 amu. You multiply the mass number by the abundance percentage and add them with the abundance of the other isotope times its mass. Since the atomic mass is closer to Cl-35 it shows that it is more abundant then Cl-37.
2.Cl-35 and Cl-37 both share the same number of protons and neutrons within the nucleus. The isotope of Cl-35 is Cl-37 this happens when there are more neutrons in the nucleus added to the atomic mass.
3. Mass number and atomic mass differ in that atomic mass is the mass of one element, simply the elements wieght. The mass number isthe added wieght of another individual element. For example CuCl2 (copper chloride) mass is the added mass of Cu's atomic mass times how many Cu atoms you may have plus that of Cl because of the ionic bond you have to elements to add.
Enrichment:
1. A spectrometer is an instrument used to measure  characteristics of individual molecules. A mass spectrometer converts them to ions so they can be moved  and manipulated by electric and magnetic fields.
2. Natural uranium is only 0.7% uranium-235, a type of uranium that undergoes fission in this type of reactor.The reactor uses Uranium as fuel, and  heat is generated by nuclear fission (neutrons smash into the nucleus of the uranium atoms) split roughly the uranium atom in half and release energy in the form of heat the rest is U-238.Modern reactors use "enriched" uranium fuel, which has a higher proportion of U-235.

7-3 Periodic trends Activity

• Atomic radii trend decreases as you move from left to right. This is because the left of the table contains metals with a weak attraction for electrons. Meaning the electrons radius is farther away from the nucleus this is what makes it easier for metals to loose electrons.The heavist elements in a period have the smallest radii because the electrons are more attracted and closer to a larger mass pulling the electron shells closer.
• Elements at the bottom  of a group have the lowest electronegativity because it is the most metallic having the smallest ionization energy Making it easiest for the element to loose electrons.
• The non-metals are harder to take an electron away than metals because non-metals want to gain electrons, whereas metals want to loose their electrons.
• Trends are referred to as periodic because it represents a pattern that happens in the elements throughout a certain period hence the "periodic table".