Titration Lab

July 6, 2015

The purpose of this lab was to find the percent ionization of vinegar. To find the percent ionization, the volume of NaOH or sodium hydroxide. Using titration to see how much of NaOH made the liquid into a slight pink color, the the volume was discovered to be 27.1 on the first trial and 26.3 on the second trial. The pH of vinegar was given to be 2.4. With all this information in mind, the MV = MV equation could be used to find the molarity of acid.

Trial 1: (X M) (7.3) = (0.25 M) (27.1)  --> 0.94 M

Trial 2: (X M) (8)    = (0.25 M) (26.3) --> 0.82 M

Average Concentration of the vinegar = 0.88 M

[H3O+]  = 3.98e-3

The percent ionization was 0.45% found by dividing the hydrogen ions in vinegar water by the CH3COO- times 100 to find the percent.

The percent ionization was so small because the acid is a weak one.

Soluibility: A Guided Inquiry Lab

July 5, 2015

Introduction:

The purpose of the lab was to identify unknown solid. To identify the solid, the mysterious substance was placed in water to obtain its solubility. Heating water to 44 degrees Celsius, the substance was placed and stirred to see if it would dissolve. Our first attempt dissolved with 3.8 grams of the substance proving that the solid was indeed not NaCl (the lowest solubility possible outcome). Then 3.2 grams were then added to the water for the second trial and it also dissolved, canceling the option of KNO3. The final answer due to elimination was NaNO3.

Procedure:

Materials- hot plates, balances, thermometer, beakers, erlemeyer flasks, stirring rods

1. Pour beaker with 10 mL
2. Put large beaker with 20 mL underneath
3. Heat water to 44 degrees C
4. Add 3.8 grams and check if it dissolves
5. If dissolved, add 3.2 grams and check if it dissolves

Data

Test #1 
 3.8 grams of substance- dissolved --> This canceled out the possibility of NaCl

Test #2
3.2 grams of substance- dissolved-->This canceled out the possibility of KNO3, leaving only NaNO3.

Discussion/Concluding Summary:

The substance found was NaNO3, beacause the solubility levels were on par with NaNO3 which was the only remaining possibility left. The higher the temperature, the solubility also increased.

Alka Seltzer and the Ideal Gas Law

    The purpose of this lab was to determine the mass of the CO2 produced. Using a balloon and 3 Alka Seltzer tablets, we were able to measure the amount of CO2 by measuring the circumference of the balloon and filling it with water till it matched the circumference of the Alka Sletzer tablet sized balloon. 

Analysis Questions

1. We spilled some powder and spilled water on the first attempt.

2. Spilling powder would make "n" a smaller quantity.

3. The volume was 896 cm3/mL.

4. It was mucho close. I believe the actual one is accurate because the balloon is not a perfect sphere.

5. A real gas interacts with others while an ideal is independent of others. In an ideal gas actual volume taken up by the molecules of gas is not taken into account. 

6. No, the ideal gas would not interact with others.

Advanced Questions

1. 2.06 grams is the mass of CO2 that should be collected.

2. 76.7% is the percent yield for the for the CO2. 

3. Our calculations would mean it was less than the actual value since the CO2 dissolved. 

Calories in Food Lab

    In this lab, we were to calculate how many calories three types of food contained. To do so, using measurements for the cashew, pecan, and cheese puff for both after being burned and before was essential. Also a constant 22 degrees for water was established. After the water was burned, the temperature of the water was measured to calculate the change in temperature. At the end, cashew was found to contain 960 calories, Pecan to be 1450 calories, and cheese puffs to be 350. 

Evaporation and Intermolecular Attractions

July 29, 2015