Question

What is the pH number of the hydrochloric acid?
A.Below 7
B.Above 7
C.7
D.Between 8 and 10

Answer 1

Hint: In chemistry, pH is defined as a scale used to specify the acidity or basicity of an aqueous solution. Lower pH values correspond to solutions which are more acidic in nature, while higher values correspond to solutions which are more basic or alkaline. At room temperature, pure water is neutral and has a pH of 7.

Complete step by step answer:
The term pH refers to the potential of hydrogen ions in a given solution.The pH of a substance is mathematically given as the negative of the logarithm of the concentration of hydrogen ions. In terms of hydronium ion concentration, the equation which is used to determine the pH of an aqueous solution is:
\[pH=-\log \left[ {{H}_{3}}{{O}^{+}} \right]\]
The pH of acid is given by the pH scale from 1-7 from 1-14 scale at room temperature. As the strength of acids increases the hydrogen ions in the solution increases, thus, their negative logarithm or pH decrease. By moving down the scale from 7 to 1 the concentration of the hydrogen ion. \[HCl\] is highly acidic and gives up hydrogen ions in solution so it has pH less than 7 while on this scale basicity increases going from 7 to 14. So all the acids strong or weak have pH under 7.
Hence, the correct answer is option A.

Note:
Hydrochloric acid or muriatic acid is a colourless inorganic chemical system with the formula \[HCl\]. Hydrochloric acid has a distinctive pungent smell. It is classified as strongly acidic and can attack the skin over a wide composition range, since the hydrogen chloride completely dissociates in an aqueous solution.