5 ml. of 0.4 N NaOH is mixed with 20 ml. of 0.1 N HCl. the pH of the resulting solution will be

Concept:pH (Power of Hydrogen): The degree of acidity or alkalinity of a substance is expressed in pH value.pH is a scale (0 to 14) used to specify the acidity or basicity of an aqueous solution.Lower pH VALUES of solutions represent more acidic in nature,While higher pH values of solutions represent more basic or alkaline.Normality: It is the concentration of a solution expressed as no. of GRAM equivalents per litre solution.\({\RM{Normality}} = \frac{{{\rm{Gram\;equivalents}}}}{{{\rm{volume\;of\;solution\;in\;liter}}}}\)Where, \({\rm{No}}.{\rm{\;of\;gram\;equivalents}} = \frac{{{\rm{Given\;weight}}}}{{{\rm{Equivalent\;weight}}}}\)\({\rm{And\;equivalent\;weight}} = \frac{{{\rm{Molecular\;weight}}}}{{{\rm{Valency}}}}\)Calculation:Given that, Volume of 0.4 N of NaOH = 5 mlNormality NaOH = 0.4 NVolume of 0.1 N of HCL= 20 mlNormality HCL= 0.1 NThus number of milligram of NaOH = 5 x 0.4 = 2 mgThus number of milligram of HCL= 20 x 0.1 = 2 mgHence the concentration of NaOH and HCL is in 1:1 ration, which means the reaction of strong ACID HCL and strong base NaOH is expressed as NaOH + HCL → NACL + H2OThe shows that the resultant solution will be neutral with pH value 7The scale runs from 0 to 14, with acids having a pH less than 7, 7 being neutral, and bases having a pH higher than 7.Acids and bases react with each other in what is called a neutralization reaction.