what is the meaning -PH?

Question

do we have PH= -4 and what is the meaning

Answer 1

What your thinking of is "pH", not "PH" which is simply the -log of the [H+ concentration]. It is a chemistry term, and is used widely throughout the sciences as a measure of basicity, or acidity of a solution

*NOTE* in Chemistry, if theres a 'p' before anything, it means -log[of whatever comes after that pH]. For example, pH is the -log[H+], pOH is the -log[OH-], and pKa/pKb is the -log[Ka]/-log[Kb) respectively. The 'p' is used when you are working with exponential numbers. It gives a way to translate those large numbers to smaller ones, easier to read numbers.

The pH scale goes from 0 to 14, but it can jump outside that scale - eventhough it isnt likely. The lower end is acidic, whereas the higher end is basic. If a solution with a pH = -4 were to exist, this would be extremely acidic, and most likely very dangerous and explosive.

Answer 2

pH = -log(base 10)[H+] The 'p' comes from 'potenz', German for 'power' (as in the nth power of a number ... given, I suppose, that pH is related to the 'power of 10' of the concentration). And the 'H' from the symbol for hydrogen. pH below 7 is an acidic solution; pH of 7 is neutral; and above 7 is basic.

Answer 3

acidity is caused by presence of hydrogen or H+ ions and basisity is caused by presence of OH- ions but their concentrations in solutions usually range from 10^-14 to 10^-1 moles per liter and since the values are very small it was tough to do calculations based on them and tough to express its strength then the pH scale was determined which was defined as the negative logarithm of the concentration of h+ so basically the larger the concentration of h+ the smaller the pH so strong acids have low pH and since the pH is a simple no between less than 14 it was easy to handle in water the concentration of h+ and oh- are equal thus it is neutral and its pH is 7
the pH scale

acidic basic
---------------------7-----------------------14

Answer 4

PH is the acidity of something. water has a PH of 7 below that is a base above that is an acid Ph balance mens nothing. what is negative PH?

Answer 5

here's hoping this is what you were looking for ...

pH is the short form for potential hydrogen. The pH of any solution is the measure of its hydrogen-ion concentration.

The higher the pH reading, the more alkaline and oxygen rich the fluid is.

As for the -4, you got me on that one.

The lower the pH reading, the more acidic and oxygen deprived the fluid is. The pH ranges from 0 to 14, with 7.0 being neutral. Indicator above 7.0 is alkaline and below 7.0 is considered acidic.

Answer 6

pH or potential of Hydrogen is merely the negative logarithm to the base 10 of the hydrogen ion concentration in moles per liter. The pH value ranges from 1 to 14, inclusive. There can never be any negative value.

Answer 7

pH I think stands for "parts Hydrogen." If it has a lower amount, it's more acidic. If it has a higher amount, it's more basic. I believe 6 or 7 is neutral. So 4 would be acidic.

Answer 8

we dont have pH = -4 and you can get that reading from pH meters and its not true,, pH means the - log of H and H is the concentration of hydronium ion in the solution

Answer 9

pH measures the acidity or base of a substance, it ranges from 0-14, 0 beings the most acidic, and 14 being the most base. Neutral is supposedly at 7, water is at 6.8 or something.

Answer 10

I've just answered this to:

http://answers.yahoo.com/question/index;_ylt=Avms7uTL0c0eNPsRK0ywluzsy6IX?qid=20060812020925AAKy9Ye

specifically pH=-4 would mean that you have 10000 M which is impossible... Scale is from 0 to pKw where pKw is the negative logarithm of the ionization equilibrium constant of water. At room temperature pKw=14