# What is pH? What does mean by pH?

In practice, pH of any liquid can is measured directly by using pH meter. A figure expressing the acidity or alkalinity of an answer on a logarithmic scale on which 7 is neutral, lower values are more acid, and higher values more alkaline.

But is a big question what does mean pH? What is the meaning of pH 5 or 10.actually pH is the relative amount of H+ in a solution.it is defined; pH is the negative logarithm of H+ in a solution.it measures the moles of h+ solution.

Since pH =-log (H+)

##### Therefore

PH=0; then (H+) =1×100=1 or greater mols H+ per liter

PH=1; then (H+) =1×10-1=0.1 mols H+ per liter

PH=2; then (H+) =1×10-2 =0.01 mols H+ per liter

PH=3; then (H+) =1×10-3 =0.001 mols H+ per liter

PH=4; then (H+) =1×10-4 =0.0001 mols H+ perliter

PH=5; then (H+) =1×10-5 =0.00001 mols H+ per liter

PH=6; then (H+) =1×10-6 =0.000001 mols H+ per liter

PH=7; then (H+) =1×10-7=0.0000001 mols H+ per liter

PH=8; then (H+) =1×10-8=0.00000001 mols H+ per liter

PH=9; then (H+) =1×10-9=0.000000001 mols H+ per liter

PH=10; then (H+) =1×10-10=0.0000000001 mols H+ per liter

PH=11; then (H+) =1×10-11=0.00000000001 mols H+ per liter

PH=12; then (H+) = 1×10-12=0.000000000001 mols H+ per liter

PH=13; then (H+) =1×10-13=0.0000000000001 mols H+ per liter

PH=14;then (H+ )=1×10-14=0.00000000000001 mols H+ per liter

Similarly, pOH can be defined as pOH is the negative logarithm of OH in a solution.it measures the amount of OH per liter of solution

Since pOH=-log (OH)

##### Therefore,

pOH=0;then (OH)=1×100=1 or greater mols OH per liter

pOH=1;then (OH)=1×10-1=0.1 mols OH per liter

pOH=2;then (OH)=1×10-2=0.01 mols OH per liter

pOH=3;then (OH)= 1×10-3=0.001 mols OH per liter

pOH=7;then (OH)=1X10-7=0.0000001 mols OH per liter

pOH=10;then (OH)=1×10-10=0.0000000001 mols OH per liter

pOH=14;then (OH)=1×10-14=0.00000000000001 or smaller  mols OH per liter

PH Value designate the medium condition

PH, 0-3=strong acidic

PH, 4-6=weakly acidic

PH, 7=natural

PH, 8-10=weakly alkaline

PH, 11-14=strong alkaline