I don't really understand the pH scale. I don't get how it happens or what its pupose is?

Answer 1

its a scale of 1-14. Pure Water is a 7. Low Ph is and Acid. high ph is a base. Low ph coresponds with a high hydrogen ion count.
It helps people know the acidity of something like creek water. or how much of a base is sea water. the whole happens part of the question idk.

Answer 2

The pH scale ranges from 0 to 14. It measures the acidity or basicity of a solution. A pH of 7 means it is a neutral solution. Pure water has a pH of 7. A pH of less than 7 means the solution is acidic. A pH of more than 7 means the solution is basic. The less pH, the more acidic the solution is. The more pH, the more basic the solution is.
pH stands for the power of H, or the amount of H+ ions acids or bases take or contribute in solution. pH equals the negative log of the concentration of H+.

pH = -log[H+]

When the concentration of H+ ions in a solution is 10-14, the pH is 14. In pure water, the average concentration of H+ ions is 10-7.

Try the animation and then read the text for a complete explanation of pH.



This is a rough measure the acidity of a solution. The "p" stands for "potenz" (this means the potential to be) and the "H" stands for Hydrogen. So you must write pH with a lower case (little) p and an upper case (capital) H. Writing PH would mean a public house! Writing Ph would mean philosophy as in PhD which means a Doctor of Philosophy.

The pH of distilled water is 7, this is neutral. Any solution with a pH below 7 (i.e. pH 1.0 to pH 6.9) is an acid and any solution with a pH above 7 (i.e. pH 7.1 to pH 14) is an alkali.

Acidic solutions have a pH between 1 and 6.9 === your stomach contains HCl it is pH2.

Alkaline solutions have a pH between 7.1 and 14. === your small intestine is pH 9.

Neutral solutions are neither acidic nor alkaline so their pH is 7.

The pH scale was invented a long time ago and sometime it seems a little silly that the more acid it is the lower the pH is. Really it is quite easy. Acids all produce Hydrogen ions (H+). Acids like Hydrochloric acid produce lots of Hydrogen ions; this is because when Hydrogen Chloride gas dissolves in water the molecules of Hydrogen Chloride dissociate into Hydrogen ions and Chloride ions.

HCl(aq) = H+ + Cl-

Water also dissociates to produce ions, this time it is Hydrogen ions and Hydroxyl ions.

H2O(l) = H+ + OH-

Sodium Hydroxide also dissociates to produce ions when it is dissolved in water, this time it is Sodium ions and Hydroxyl ions.

NaOH(aq) = Na+ + OH-

In each case we can measure or calculate the concentration of Hydrogen ions present. We use the symbol [H+], we use square brackets to mean that it is the concentration of Hydrogen ions.

In HCl(aq) Hydrogen Chloride solution or Hydrochloric acid [H+] = 0.01

In H2O(l) water [H+] = 0.0000001

In NaOH(aq) Sodium Hydroxide solution [H+] = 0.00000000000001



As you can see, these numbers are very silly (well the first one might be OK but not the second two). So what we do is count the decimal places.

HCl(aq) pH2

H2O (l) pH7

NaOH (aq) pH14

There is a lovely advert on TV (or there was) in which the advertisers said that their shampoo was the best because it had very low pH. This means it is very acid, but you would not put it on your hair if they told you that it was acid. I think that the advertisers think that you must be stupid and that you will use their shampoo because it has low pH.

So to recap if the pH is low, it means that there is a high concentration of Hydrogen ions and if the pH is high it means that there is very low concentration of Hydrogen ions or none at all. Water and other neutral solutions are in the middle at pH7.


The gentleman who invented the pH scale wanted to measure how acid his beer was. As you know you have to use yeast to make beer or wine, and you also know that yeast uses enzymes. Enzymes only work if the pH is right. What he discovered was that acids and alkalis make the colours in plants change. The easy one is Litmus paper. Try grinding up some red cabbage or a beetroot. You will get a red or blue liquid. You can make the liquid change colour by adding acids or alkalis. All that happens is that the colour of the plant dye depends upon the concentration of Hydrogen ions. If you have used universal indicator paper you know that it can change from blue to green to yellow to red. Universal indicator is a mixture of dyes which all change when you change the pH.

Answer 3

It is easy, you just have to remember it is for finding how acidic or basic something is. There is a scale of 1 to 14, 1 (stomachh acids) being the most acidic and 14 the most basic. 7 is neutral (water). The lower the number the more acidic and the higher the more basic. From one number to the next is ten times more acidic. Say from 5 to 4, 4 is 10 more acidic than 5. 8 to 6 (2 places so 10*10), 6 is 100 times more acidic than 8. That is just about all that is needed for the pH scale.

Answer 4

Basically a pH scale measures the concentration of H+ and OH-. The pH of a solution is defined as a negative logarithm of the hydrogen ion concentration and the pH scale measures this and places a value on it ranging from 0 to 14.


The pH scale was developed because the concentration of the solution can vary by so many factors they found over time, and a pH scale was the easiest way to express the variation of the solution.



The pH scale ranges from 0 to 14. The 0 end of the scale is where the concentration is increasingly acidic. Moving up around 2 is lemon juice and stomach juices. Then around 3 are vinegar, beer and cola. Next at 4 is tomato juice. Then at 5 is black coffee and rainwater. Followed by urine at 6. Pure water and human blood are at 7. After 7 the concentration starts to become more basic as it heads up the scale. Most biological fluids are between pH 6 and pH8, there are a few exceptions to this like stomach acid.


Then between 8 and 9 is seawater. Then at 10 is milk of magnesia. Followed by household ammonia at 11, household bleach at 12. Then between 13 and 14 is oven cleaner. Products at the two extremes (less than pH 1 or greater than pH 13) are extremely oppressive and corrosive. Examples include, sulfuric and hydrochloric acid on the acid end, and caustic soda on the alkaline end. Use solutions of phosphoric or sulfamic acid cleaners, typically in the pH range of slightly less than 2, may be described as "safe" acids comparison to the stronger acids.


The internal pH of most living cells is close to 7. When there is even a slight change in the pH, this can be extremely harmful. It is harmful because the chemical processes of the cell are sensitive to the concentration of hydrogen and hydroxide ions. Biological fluids can resist change to their own pH when acids and bases are introduced because of the presence of buffers. Buffers in human blood for example maintain the blood pH very close to 7.4.


A person cannot survive if the pH of their blood drops to 7 or rises to 7.8. Under normal circumstances the buffering capacity of the blood prevents such swings in the pH level.


An acid adds hydrogen ions to a solution, but it also removes hydroxide ions because of the tendency of H+ to combine with OH- to form water. The base has the opposite effect with an increasing OH- concentration but also reducing the H+ concentration by the formation of water.


Each pH unit represents a tenfold difference of the H+ and OH- concentration. It is this mathematical feature that makes the pH scale so compact. For example a solution of pH 2 is not twice as acidic as a solution of pH 4, but a hundred times more acidic. So when the pH of a solution changes slightly, it actually changes the concentrations of H+ and OH- substantially.

Answer 5

ph scale show the acidicity of a substance. if hger then 7 then the substance is a alkaline meaning it reacts with acid to produce a salt and water. if lower then 7 on the ph scale the substance is an acid meaning it reacts with an alkaline to make a salt and water. if the substance is 7 then it is neutral meaning its harmless to touch. the ph scale shows how strong of a acid or alkali is. something of ph 3 is 10x more acidic then something with a ph of 4 as it is a logarithmic scale. ph is used to find out how harmful a substance is, wether it would react with an acid or a alkaline, and to find the concentration of h+ ions when a acid dissolved in water, or oh- molecules in a alkaline

Answer 6

A pH scale is a "meter" used to determine the acidity or alkalinity of a compound, preferably a solution. It ranges from 1(most acidic) to 14(most alkaline). These pH scales usually work with colour change, when an indicator is used with it.

Answer 7

The Ph scale shows the acidity or alkilinity of any substance with 1 being the most acidic and 14 being the most alkaline.

Answer 8

the ph scale is a scale that tells you how much alkaline and acid there is, 1 is most alkaline and 11 is most acid and in the middle is 7 this is neutral.

Answer 9

Its purpose is to show whether the substance is acidic, alkaline, or neutral.
It has values from 0 to 14
From 0 to 7 it shows that the substance is acidic(o being the most acidic and 6-7 means least acidic), 7 means neutral, and 7-14 shows that the substance is alkaline( 7 being least alkaline and 14 being most alkaline).

Answer 10

it is simply a scale for registering the ph of something.