What does the pH level of a drink show about it?
pH level of a drink shows its nature as to ascertain whether it is fit enough for consuming or drinking. To make this understanding clearer we should look into what pH of a solution means
Consider Ionization of pure water ,
H2O ? H2 + O2
here ,there is poor ionization producing small but equal concentration of H? and OH¯ ions or [H?]=[OH¯]=10-7 g ion per litre.
Since both concentrations are equal , pure water is neither acidic or basic, rather it is neutral. If in a solution, [H?] > [OH¯] ,the solution is acidic or if [OH¯]>[H?],the solution will be basic
[H?] is smaller than 10-7 g ion per litre , it will be basic.
[H?] is equal to 10-7 g ion per litre , it will be neutral.
[H?] is greater than 10-7 g per litre ,it will be acidic.
Therefore the acidity or alkalinity of a solution can be expressed in terms of 10-x , where 'x' is hydrogen ion concentration in g ion per liter ; If 'x' is less than 7 , the solution is acidic and if it is more than 7,the solution is basic .
Now why pH scale is introduced? It is because this method of interpreting or representing the acidity or alkalinity of a solution is cumbersome.
A simple and convenient method was proposed by S.P.L. Sorensen. In pure water [H?] =10-7 g ion per liter.
We can write
or -log[H?]= -log[10-7 ]=-(-7)=7
Now -log is denoted by p, so we can write:
- log [H?] = pH =7.
It means that pH of pure water is 7, suppose in a solution, [H?] is 10-9 g ion per liter, that is smaller than 10-7 g ion per liter, so that the solution will be basic.
pH = -log [H?] = -log10-9 = - (-8) =8.
Similarly if in a solution, [H?] is 10-3 g ion per liter, which is greater than 10-7 g ion per liter, so pH = 3 and this solution will be acidic.
Now to define pH , we can use logarithm with hydrogen ion concentration.
pH value of a solution is defined as the negative algorithm of its hydrogen ion concentration in g ion per liter.
-log [H?] = pH= log1/ [H?] pH stands for potential hydrogen.
Now pH value of a drink implies a lot about the drink.
It tells about the constituents of the drink, the elements present or the compound concerned. For example take a drink whose pH value is less than 7.Since we know its value we can guess it has non metals or it has non metallic oxides, may be carbonated drinks. We know that non metallic oxides are acidic in nature while metallic oxides are basic in nature. Thus pH gives this idea about its constituents.
It gives the idea about the source of the drink. Suppose any sample of water which ha pH value of 6.5 or less then it can be concluded that the minerals present in the sample are acidic in nature ,the source could be ground water of any typical region .Value less than this can signifies that this is not fit enough for drinking, unless otherwise stated.
Same goes with pH value of 8.3 or between 7 to 8.3, it shows that it is slightly basic in nature, and there is presence of carbonates in the solution.
Higher value on either side of the scale shows that the drink has extraordinary elements responsible for its behavior which, generally speaking may not be fit for drinking unless otherwise stated .These could indicate toxins in the drink. Medicines or bears or alcohols or room cleaners may show the extreme value at times. But generally it is advisable to not consume such drinks which typically depict extreme value of pH on either side of the scale 1 to 14. (pH scale )
pH value also give the information of hardness or softness of water .It gives the idea of total permanent hardness or total temporary hardness present in the drink sample .it means total amount of metal carbonates or bicarbonates present in the drink sample. This hardness has typical implications in usage of the drink. For example if this is consumed for considerable period of time it can give rise to typical or specific health issues in our body like stones, malfunctioning of internal organs like liver or enzymatic glands or pituitary glands. It can lead to permanent failure of organs. Also as far as short term consequences are concerned this hard water has quite bitter taste which can make food very tasteless. This hard water is also not fit for washing clothes. So with help of pH we can ascertain whether the drink can be used for performing above mentioned task or not.
pH of the drink gives the light while studying and performing the quantitative and qualitative analysis of the drink. Together with other parameters like color, odour , taste, density, viscosity , surface tension, temperature , turbidity , form and froth , conductivity , dissolved solids , redox potential, the value of pH is very helpful in determining the physical properties of the drink. It is so helpful that it gives the idea to how to proceed in testing of chemical properties of the drink , which reaction to carry out and what should be the medium of reactants' mixture or solution.
The Biological importance of pH is that it gives the idea to find out the pH value of other drinks or solutions .There are many biological or plant pigments which act as pH Indicators or natural pH indicators. The pH of blood is 7.4 .Any alteration can have severe consequences as blood is major connective tissue in body .While going for check up the pH of blood is also checked, though it is a buffer .The body System is capable of managing small alteration in blood pH but just small alteration.
In a nutshell pH of a drink is extremely valuable information of any drink.
1.Analytical chemistry theory and practice by R.M. verma
2.Inorganic chemistry by J.D Lee