Lab 7: Flame Test Lab

In this lab, we wanted to determine two compounds using flame tests to compare the flame colors various compounds produced. We held wooden sticks over the flame of the Bunsen burner and the  compound on the stick changed the color of the flame. We used the flames colors of known compounds to identify the unknown compounds. 
 
Pre-Lab Questions:
1. Ground state is the most stable energy state where all the electrons are in the lowest energy levels available. This normal electron configuration differs from excited state, which involves the "jumping" of electrons to higher energy levels due to the absorption of energy from heat at high temperatures. The excited configuration is very unstable and electrons will eventually "drop" to positions of lower energy.

2. Emit means to produce or discharge. For example, the sun emits radiation which means it produces and releases radiation.

3. Atoms are getting their excess energy from the heat of the flame. The flame from the Bunsen burner is exciting the electrons of the substance.

4. Atoms of different substances release different amounts of energy while the electrons are falling back down to ground state. A specific number of electrons in an atom release a certain amount of energy which changes the color of the light produced by a compound.

5. You need to clean the wire to make sure no residue is left from the previous substance. If the cation of the last compound still remained on the wire, it could change the color produced by a mixture of compounds. The wire would not create clear and accurate data.

A picture of Unknown #1 in the flame

Unknown #1: LiCl
Unknown #2: KCl
We were able to identify the unknowns by comparing the color of the flame created by the unknowns to the color of the flames we recorded from our 8 known compounds. We found that unknown #1 created a magenta color flame, just like LiCl did and unknown #2 created a light purple flame, just like KCl did.

Lab 8: Electron Configuration Battleship

The biggest challenge I had was naming elements in the f- block. I continually chose the wrong noble gas when trying to name the correct row in the f block. For example, I would accidently use Radon to name the 4Fs, but Radon is actually the noble gas before the 5Fs. During this challenge, I learned how to properly name the noble gas configurations of elements in the Lanthanides and Actinides.

Lab 6: Mole-Mass Relationships Lab

The purpose of this lab was to practice calculating theoretical yield and percent yield using our experimental data. We also had to find the limiting reactant of NaHCO3(s) + HCl(aq) => NaCl (aq) + CO2(g) + H2O(g) by looking at the relationship between the reactants and how much product they each produced. Overall, we found that NaHCO3 was our limiting reactant and we were able to successfully have a 100% yield.

Questions #1-#4

 

 

Even though our percent yield was 100%, I believe we did lose some mass when our remaining solid product popped once on the hot plate, but the small amount of water still left in the evaporating dish made up for that lost mass. The fluctuating of the scale is also another reason that error may occur and it could've possibly affected our percent yield if we did not read the scale as accurately as we did.

 

 



My lab partner and I also found it interesting that when we touched the tongs to the remaining solid in the evaporating dish, the solid turned into a yellow-green color due to contamination. 

 

Lab 5B:Composition of a Copper Sulfate Hydrate Lab

Before heating

After heating

Calculations for Questions #1-#4

Possible explanations for percent error include the false reading of the scale while it was fluctuating or not waiting long enough for all the H2O to evaporate.

Question #5
Moles of water evaporated- 0.014 mol H2O
Moles of CuSO4- 0.0032 mol CuSO4
Ratio of moles of CuSO4 to H2O- 1:4
Empirical formula- 1CuSO4 is loosely bonded to (dot symbol) 4H2O
We predict our predicted coefficients are slightly low compared to the actual value, even though our percent error isn't high.  To have a percentage of water closer to 36%, more water needed to be lost and therefore the ratio of Copper Sulfate to water would increase. 

Lab 5AL Mole Baggie Lab

In this lab, we needed to determine mystery substances in plastic bags using given measurements of the substance. We began by weighing the filled bag on the scale to find the total mass, and then we also used our given total mass to find the mass of our substance. For Set A, we calculated the molar mass by dividing the mass of the substance by the given number of moles. For Set B, we first converted the given number of respective particles to moles, and then we calculated the molar mass using the same given formula. Next we compared our calculated molar masses to the molar masses of the possible compounds. Our results were A4 is Calcium Carbonate and B3 is Potassium Sulfate.

Lab 4A: Double Replacement Reaction Lab

Complete molecular and net ionic equations #1-#5



Complete molecular and net ionic equations #6-#10

 



My well plate

 In this lab, I was surprised on how easy it was to write net ionic equations. After I completed writing the molecular equation for each reaction, I used any solid products to write a separate net ionic equation beneath. The shortcut of breaking down the solid compound to its separate polyatomic ions and elements made it very easy to write the net ionic equation. The most challenging part of this lab was finding out the solubility of each compound in the complete molecular equations. I needed to continually look at the solubility rules to find out what compounds were insoluble or soluble. The many exceptions in the solubility rules made this even more challenging.

Lab 3: Nomenclature puzzle

The goal of this lab was to complete a puzzle by matching binary and polyatomic ion formulas to their name. This puzzle was good practice on using the naming rules we learned in class today. The biggest challenge during this activity was searching for certain names that were already part of small groups. At the beginning, it was more simple to match names and formulas because we divided by the triangle pieces by the elements on the triangle, but it became more difficult as more and more small groups formed. I believe my biggest contribution to the group was putting the small groups of triangles together, making it easier to find certain triangles. I also helped assign certain elements to certain people, making the process flow more quickly.

Our completed puzzle