Question

What is the pH value of acid?
A. <7
B. >7
C. =7
D. None

Answer 1

Hint : The pH of aqueous or other liquid solutions is a quantitative measure of their acidity or basicity. The phrase, which is frequently used in chemistry, biology, and agronomy, converts hydrogen ion concentrations, which typically vary from around $1{\text{ }}to{\text{ }}{10^{ - 14}}$ gram-equivalents per litre, into numbers between 0 and 14.

Complete Step By Step Answer:
pH is a scale used in chemistry to describe the acidity or basicity of an aqueous solution. The pH of acidic solutions is lower than that of basic or alkaline solutions.
The pH scale is logarithmic, indicating the concentration of hydrogen ions in a solution in inverse order. The range is, with 7 being the neutral value. Acidity is indicated by a pH less than 7, while a pH greater than 7 indicates a base. pH is a measurement of the proportion of free hydrogen and hydroxyl ions in water.
The hydrogen ion concentration in pure water, which is neutral (neither acidic nor alkaline), is ${10^{ - 7}}$ gram-equivalents per litre, which corresponds to a pH of 7. A solution with a pH of less than 7 is acidic, while one with a pH of greater than 7 is basic, or alkaline.
Hence from the above gathered information we can conclude acid has pH value less than 7 i.e.( >7)
So, the correct option is B.

Note :
Because the physical significance of the hydrogen ion concentration is unknown, the pH is defined operationally, that is, it is based on a measurement method. pH values are determined by the National Institute of Standards and Technology in terms of the electromotive force that exists between certain standard electrodes in specific solutions.