Concentration of a Solution: Beer's Law

Objective:  Determine the concentration of an unknown nickel (II) sulfate solution.

Materials:
              Logger Pro, Vernier Colorimeter, Cuvette, 20x150 mm test tubes, 30mL of .40 M NiSO4, 5 mL of NiSO4 unknown solution, two 10 mL pipets, Distilled water, Test tube rack, two 100 mL beakers

Procedure:
              First we were explained the lab and we were demonstrated the unknown solutions. But before figuring those out we were to find five trail numbers first. In this trial number we were supposed to find which one is more concentrated.
   Trail  .40 M NiSO4    Distilled H2O    Concentration                            
     1             2                        8                       .08
     2             4                        6                       .16
     3             6                        4                       .24
     4             8                        2                       .32
     5             10                      0                       .40
Open logger pro and for each solution test the vertical axis has absorbance and the horizontal is the concentration. Collect the data.

Data:
  

Conclusion:
     The concentrations of the solutions were determined in this lab.

Acid-Base Titration

Titration- The process used to determine the volume of a solution needed to react with a given amount of another substance.

Purpose- Determine the unknown concentration of HCI, the concentration of NaOH will be given.

Materials- Logger pro, vernier pH sensor, HCI solution,  .100 M NaOH solution, magnetic stirrer, pipet, distilled water, goggles

Procedure- First we used a pipet with 10 mL of the HCI solution into a 250 mL beaker and added 50 mL of distilled water. Then we placed the beaker on the hot plate with a stirrer. After that used a utility clamp to suspend a pH sensor on a ring stand and postioned the pH senor in the HCI solution. Slowly while it was warming up we added NaOH solution and graphed each point. We did this until it was a full balanced acid. We knew this happened by the color it turned. Then we figured out the numbers and knew we did a pretty good job.

Data-

               The calculations:
Concentration of NaOH at beginning:                                 0.1 M
Volume of NaOH at equivalency point:                               15.51 mL or .01551 L
Moles of NaOH at equivalency point:                                 .001551 mol
Moles of HCl at equivalency point:                                     .001551 mol
Concentration of HCl at equivalency point:                          .1551 mol/L


Conclusion:  In conclusion this lab taught me about acids and bases.

Animal Inspired Robots

Percent Composition, Empirical and Molecular Formulas, Hydrates take 2

Evaporation and Intermolecular Attractions

Goal:
   The goal in this lab is to study temperature changes caused by evaporation. The temperature changes will be related to the strength of intermolecular forces of attraction. The results will predict, then measure, the temperature change for several other liquids. Also we will study the molecular structures of alkanes and alcohols for the two intermolecular forces known as hydrogen bonding and dispersion forces.

Material:
   Mac Computer                                                              two small rubber bands
   methanol                                                                       masking tape 
   Serial Box Interface                                                      ethanol
    Data Logger                                                                 1-propanol
   Two Vernier Temperature probes                                 1-butanol
   6 pieces of filter paper                                                   n-pentane
   n-hexane

Procedure:
    First prepared the computer so we could get our data. Then we gathered all the materials and started the experiment. Wrapped probe 1 and probe 2 with filter paper and to hold it together we used the rubber bands. Then we put probe 1 in methanol and second one in ethanol. Let them soak for about fifteen seconds. After that we took the probes out of the containers and  put them at the edge of the table with masking tape and recorded the temperature. To get the results we had the lower temperature subtracted the higher one and that's how we were able to determine the temperature changes for the other ones.

Methanol and Ethanol

Heptane and Hexane

Propanol and Butanol

 

 

 

 

 

     Data:

                                                       


Analyzing the Data:
       
            In the alcohols studied (methanol and ethanol) Methanol had the strongest intermolecular forces attraction and ethanol had the weakest. Methanol has the ^t of 21.9 and ethanol has the ^t of 14.3, making methanol a stronger intermolecular force attractions. (^= triangle)
            In alkanes studied (pentane and hexane) Hexane had a stronger intermolecular force attraction than pentane because the ^t for hexane is 17.5 and pentane is ^t7.5, making hexane with the stronger intermolecular force attraction. 


                                                                 
 

The Mole

Mole 

The mole is the SI base unit used that scientist use to measure a substance. But it can't be used to measure just anything. It is in better use to measure something along of the lines of the surface area of the earths depth. The mole of anything contains 6.0221367x 10^ 23 representative particles such as atoms, molecules, formula units, electrons or ions. The number 6.0221367 is  called Avogadro's number because in 1811 Amedeo Avogadro determined the volume of one mole of a gas. So basically he started the mole. The other day we conducted a lab where we had to figure out what element it was by figuring out the atomic mass and we were only given the number of moles. Then we weighed the number of grams in each cup. After getting the grams, we took the number of grams divided by the number of moles and got the atomic mass.  Then we basically knew what element it was. 
Data
Sample.             Number of moles.        Grams.           Atomic mass.      Element
     A.                            .163                         6.53            40.061                 Ca
     B.                            .910                          24.51          26.934              Al
    C.                             .160                          9.44               59                     CO
     D.                            .258                      53.90           208.9                   Bi
     E.                            .220                          14.26         64.81                 Zn 
     F.                             .756                         49.26         65.158             Zn
     G.                            .492                           28.66         58.25              Ni
     H.                             .430                    89.16         207.349           Pb
     I.                               .381                             21.28         55.85               Fe
     J.                             .259                      30.70        118.53             Sn

Example 
     Sample J.
          30.70/ .259=.      118.53=          Sn
            Grams.    Moles.   Atomic #   Element