pH

Introduction: 
The pH is a measure of the acidity or basicity of  a solution. Solutions with a pH les than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH close to 7, neutral.
Equation: pH= -log(H+)
We have different measure indicatiors of pH


Material:

-Distiled Water
-Milk
-Wine
-Lemon
-Tomato
-Carbonated beverage
-Carbonated beverage
-NaOH solution
-HCl solution
-NH3 solution
-Soap solution
-Universal indicator
-Acetic Acid
-Tongs
-Beakers 8 x 100ml and 1 x 250ml
-2 clock glass
-5 test tubes
-Test tube rack
-10ml pipet
-Funnel
-Graduated Cylinder


Objectives: 

1. Mesure different pH values of organic and inorganic solutions
2. Prove different methods of measuring pH

Procedure: 
We put the solutions in different beakers of 250. Squeeze the lemon and tomato in two clock glasses and mesure the pH. Later, we take the indicator paper and put into the beakers than have a solution and mesure the pH and compare with the others solutions the colour. (acidic, neutral, alkalin). When we have all the results, in the blackboard, we put the pH of all the solutions and we compare with the others grups of students.

Observations: 
The results of the other grups are very similated than ours and it's mean that our results of pH are good.
The pH of NaOH is 14 but in the indicator paper the maxim is 12. 
The pH of distiled water are 7, the answer of grups 3 and 4 are wrong.

2nd PART

How does concentration affect pH?

We squeeze the rest of the lemon inside a beaker and filter the solution with and cellulose paper. 

Prepare a test tub rack with 5 test tubes. We mark the tubes with letters (B, A, A1, A2, A3). 

In the tub B we put 10 ml of lemon juice. (0ml of distilated water)

In A 5ml (5ml of distilated water)

In A1 2,5ml (7,5ml distilated water)

In A2 1,3ml (8,7ml distilated water)

In A3 1,3ml (8,7ml distilated water)

pH of the tubs

A1--> 2,81 

A2--> 3,08

A3--> 3,08

A--> 2,71

B--> 2,77

QUESTIONS

1. Lemon, tomato, vinegar, coke, HCl and wine

2. NaOH and soap solution

3. Were neutral the milk, H2Od and soy milk. I spect that results in the majority but I thought the milk was alkaline before the experiment.

4. The pH 3 have more H+ than the pH. Have ten times more H+.

5. 
a) The pH i the dependent variable
b) The lemon juice concentration in the independent variable
c) Can lemon juice concentration variate the PH?
d) The test tube B, is the control of the experiment, have 100% lemon juice.
e) (No puc copiar el excel en el blog, estic intentant solucionar)















6. They have to have acid pH because their function is descomponate the aliment that you eat.

7. The blood I think that is neutral. Because if the blood is acid, the mecanism of our organism actuate to compensate and create an imbalance.

8. Is a broad term referring to a mixture of wet and dry deposition from the atmosphere containing higher than normal amounts of nitric and sulfuric acids. Acid rain causes acidification of lakes and streams and contributes to the damage of trees at high elevations. Many sensitive forest soils. In addition, acid rain accelerates the decay of building materials and paints, including irreplaceable buildings. 
The rain in Barcelona is acid.