Question

Help!! lab help!!

Calculations/Interpretations: Show all math performed (label the calculation or give the formula, show your setup, and give the result), include proper labels, and/or answer any questions listed below

*Note: You began with 5 ml of 0.1 M HCl and diluted it with 5 ml of water. To determine how many moles of HCl were in that original sample, use the formula moles = molarity x liters. Take the number of moles in that sample and divide it by the number of liters of water in which it was dissolved in test tube 1 (moles/liters = molarity). This gives you the molarity (concentration) of test tube 1. As you moved from test tube 1 through test tube 7, you took 1 ml from the first test tube and 9 ml of water. Therefore, each successive test tube has one tenth as many moles of HCl as the one before it. You will need to find the molarity of test tubes 2 through 7. Use the formula moles /liters = molarity for each test tube.

Sample Calculations:
Test Tube #1
0.1 moles/1000 mL = x moles/5 mL
x = 0.0005 moles
Molarity = 0.0005 moles/0.010 L = 0.05 M
pH = -log[H+] = -log (0.05) = 1.3

Test Tube #2
0.05 moles/1000 mL = x moles/1 mL
x = 0.00005 moles
Molarity = 0.00005 moles/0.010 L = 0.005 M


HCl 0.1 M
Test tube # concentration (M) pH
1
2
3
4
5
6
7

NaOH 0.1 M
Test tube # concentration (M) pOH pH
1
2
3
4
5
6
7

From the list above, what is the best indicator for observing pH changes for the following pHs?
pH Best Indicator
pH =2
pH = 4
pH = 6
pH = 8
pH = 10
pH = 12

Answer 1

unfortunately it's all a blur right now :/ i'm sorryyyyy. I haven't looked at this stuff in about 2 years...