Question

Please Solve Data Analysis in Table 2. Thank you.

Take seven clean test tubes from the Containers shelf and place them on the workbench.

Double-click on the test tubes to open the Item Properties window. Label test tubes 1 – 7.

Take 0.100 M sodium hydroxide from the Materials shelf and add 5 mL to test tube 1.

Take water from the Materials shelf and add 5 mL to test tube 1.

Take water from the Materials shelf and add 9 mL to test tubes 2 – 7.

Create a series of successively diluted basic solutions using the same dilution method you did in experiment 1:

Pour 1 mL from 1 into 2.

Pour 1 mL from 2 into 3.

Pour 1 mL from 3 into 4.

Pour 1 mL from 4 into 5.

Pour 1 mL from 5 into 6.

Pour 1 mL from 6 into 7.

Take bromothymol blue from the Materials shelf and add 2 drops to each test tube. Observe the color of the solutions. Record your results in your Lab Notes.

Clear your station by dragging all of the test tubes to the recycling bin beneath the workbench.

Repeat steps 1 – 6.

Take alizarin yellow from the materials shelf and add 2 drops to each test tube. Observe the color of the solutions. Record your results in your Lab Notes.

Clear your station by dragging all of the test tubes to the recycling bin beneath the workbench.

Repeat steps 1 – 6.

Take phenolphthalein and add 2 drops to each test tube. Observe the color of the solutions. Record your results in your Lab Notes.  

My question is about trying to calculate HCl concentration and then H3O and pH. What do we use for Molarity? Do I use 0.1M HCl for molarity for M1 and M2. What do I use for the volume of solution, do I use like for test tube 1 do I use 10mL for volume since I added 5 mL of HCl and then added 5mL of water?

So over all would m1 x v1= m2 x v2

0.1 M x 10mL = 0.1M x 10mL

Experiment 2: Measure the pH of Bases

Lab Results

Record your observations in the table below.

Test Tube #	Bromothymol Blue Color	Alizarin Yellow Color	Pheonlphtalein Color
1	Dark Blue	Dark Red	Dark Purple
2	Lighter Blue	Redish / Orange	Purple
3	Blue	Orange	Purple
4	Blue	Dark Yellow	Purple
5	Blue	Yellow	Lighter Purple
6	Blue	Yellow	Transparent
7	Turquize	Lighter Yellow	Transparent

Data Analysis

For each test tube, calculate the concentration of NaOH, OH^–, H₃O, and pH. You can use the following formula to determine the concentration of NaOH.
where M₁ and V₁ are the molarity and volume of the first solution and M₂ and V₂ are the molarity and volume of the second solution.
M₁ x V₁ = M₂ x V₂
Given that NaOH is a strong base, the HO^– concentration is equal to the NaOH concentration except at very low concentrations (test tube 6 and 7) where the HO^– from the dissociation of water (1.00*10^-7) becomes significant.

Test Tube #	NaOH Concentration	[HO–]	[H3O]	pH
1
2
3
4
5
6
7

Answer 1

M₁ = Initial molarity of NaOH, M

V₁ = Vol of NaOH of serial dilutions, ml

M₂ = Final molarity of desired NaOH solution, M

V₂ =  Final volume make up of desired NaOH solution, ml

TEST TUBE	M1V1=M2V2	NaOH CONCENTRATION (M)	[H3O+] = Kw/[OH-] (M)	[OH-]   (M)	pH= -log [H3O+]
1	0.1 M X 5 ml = 10 ml x M2	0.05	10-14/0.05 = 2 X 10-13	0.05	12.7
2	0.05 M X 1 ml = 10 ml x M2	0.005	10-14/0.005 = 2 X 10-12	0.005	11.7
3	0.005 M X 1 ml = 10 ml x M2	0.0005	10-14/0.0005 = 2 X 10-11	0.0005	10.7
4	0.0005 M X 1 ml = 10 ml x M2	0.00005	10-14/0.00005 = 2 X 10-10	0.00005	9.7
5	0.00005 M X 1 ml = 10 ml x M2	0.000005	10-14/0.000005 = 2 X 10-9	5 X10-6	8.7
6	0.000005 M X 1 ml = 10 ml x M2	5 X 10-6 = 50 X 10-7	10-14/51 X 10-7= 2 X 10-9	(50 X 10-7)+(1 X10-7) = 51X10-7	8,7
7	50X10-7 M X 1 ml = 10 ml x M2	50 X 10-8 = 5 X 10-7	10-14/6 X 10-7= 1.67 X 10-8	(5 X 10-7)+(1 X 10-7) = 6 X 10-7