Investigating pH

[Jessica]

Questions - Just check them...it is in a lab...


The unanswered ones...I need a hint/explanation first...thanks...



The results of diluting solutions

Tube 1: concentration was: 0.01 M (molar) HCl; pH, paper - 1; meter - 2.40

Tube 2: 0.001 M HCl; pH using paper - 6, meter - 3.30

Tube 3: 0.0001 M HCl; 6 and 4.60

Tube 4: 0.00001 M HCl; 6 and 7.40

Tube 5: 0.001 M NaOH; 7 and 9.10

Tube 6: 0.0001 M NaOH; 7 and 8.60

Tube 7: 0.00001 M NaOH; 8 and 8.70

Tube 8: 0.000001 M NaOH; 7 and 8.90

Tube with water: 10 (?) M water; 7 and 7.20

Tube 9: 0.001 M HCl + 0.001 NaOH; 7 and 8.10

Part I

1. Is the pH of a hydrochloric acid solution greater or less than the pH of distilled water? It is less.

2. As the acid is diluted, what kind of change takes place in the pH? ??Chemical change??

3. Is the pH of a basic solution greater than or less than that of distilled water? What does this mean by "basic solution"?

4. As a basic solution is diluted, what change takes place in the pH?

5. How does the pH of a mixture containing equal amounts of 0.001 M HCl and 0.001 NaOH compare with the pH of distilled water? Using the paper to find the pH, they are the same....both neutral.



Part II

1. The acid in lemon juice (has a pH of 2) is not hydrochloric acid, but if it were, what would its concentration be? 0.01

Please answer before tomorrow! I have biology 2nd pd. and I want to get a good grade on the quiz too. We are going to go over this but I don't want to be confused.





PROBLEM: How does the dilution of an acid or base affect its pH?
HYPOTHESIS: If the dilution of an acid or base affect its pH, then the acid or base is becoming more neutral.

Would my hypothesis be correct? I don't understand it...and the problem :P
What would be the balanced equation for the reaction that took place in test tube #9? Don't give me the answer...I just need help understanding.

[Jessica]

okay so no one is helping me...I will have to fill in the answers in class and I will probably fail the quiz

[Tomisimo]

Originally Posted by jchen

okay so no one is helping me...I will have to fill in the answers in class and I will probably fail the quiz

Maybe we just don't know anything about chemistry. Ask use questions about Spanish and I'm sure you'll get lots of answers . You have no reason to think you'll fail the quiz if you have studied what has been taught in class.

[CrOtALiTo]

I never was good in chemical, I can't give you some hint.

[Jessica]

Originally Posted by Tomisimo

Maybe we just don't know anything about chemistry. Ask use questions about Spanish and I'm sure you'll get lots of answers . You have no reason to think you'll fail the quiz if you have studied what has been taught in class.

mm okay then. I didn't fail the quiz....but I didn't get a perfect :P