pH Review by William Cha
This page deals with general information on pH
Are you drinking Coke or Sprite right now? Or just a cup of tea? Water? Any of these that you are drinking will probably be either acidic or basic. Properties of neutrality, alkaline, and acid are related to almost anything that you drink, with the only exception of distilled water. Here, we will explore on these three properties and pH scale
What is pH? !
pH is just a handy way to express how acidic or alkaline a water solution is.
pH is a measure of the __activity of hydrogen ions__(H+) that indicates whether a solution is __acidic __or __basic__.
Different levels of pH!
The pH scale commonly in use ranges from __0 to 14__.
low pH (0-6)= Acidic
(0-4)= Strong Acid
Neutral pH (7)
high pH (8-14)= Alkaline or Basic
(10-14)= Strong Base
Characteristics of acidic, netural, and alkaline(basic) solution!
Basic solutions have high concentrations of OH- H+<OH-
Neutral solutions have equal concentrations of H+ and OH- H+=OH-
Acidic solutions have high concentrations of H+ H+>OH-
the image below shows the different contrations of H+ and OH-
How do we measure pH levels?!
* pH can be measured by addition of a __pH indicator __into solutions. The indicator __color varies __depending on the pH of the solution. Using indicators, -qualitative determinations - can be made with universal indicators that have broad color variablity over a wide pH range and quantitative determinations can be made using indicators that have strong color variablitiy over a small pH range.
below are images of pH paper or likely to be called, 'indicators' and what different colours represent
* pH can also be measured by using a pH meter together with pH-selective electrodes (pH glass electrode, hydrogen electrode, quinhydrone electrode and other).
below is a picture of pH meter
How do different pH level relate to environmental effects? Any Examples?!
the below image will explain the environmental effects any daily examples of different solutions of different pH levels
Additional information!
Metal oxides
If a metal oxide dissolves in water, it makes an alkaline solution.
eg) sodium oxide + Water → Sodium Hydroxide
Na2O(s) H2O(l)→ 2NaOH(aq)
However, some metal oxides do not dissolve in water. These insoluble metal oxides are called bases.
Non-metal oxides
Most non-metal oxides dissolve in water to form acids.
IN GENERAL, we can say that metal oxides are basic and non-metal oxides are acidic.
Bibliography:
http://www.chem4kids.com/files/react_acidbase.html
http://education.llnl.gov/bep/science/9/tPh.html
http://www.reference.com/browse/wiki/PH
http://www.chemtutor.com/acid.htm
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