# 25.0 ml of a 0.2 M NaOH is neutralized by 12.5ml of HCl what is the molarity of HCl?

justaguide | College Teacher | (Level 2) Distinguished Educator

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The reaction that takes place when sodium hydroxide (NaOH) is neutralized by adding hydrogen chloride (HCl) is:

NaOH + HCl --> NaCl + H2O

To neutralize one mole of NaOH one mole of HCl is required. 25 ml of 0.2 M NaOH contains 0.025*0.2 = 0.005 moles of NaOH. As this is neutralized by the addition of 12.5 ml of HCl, there are 0.005 moles of HCl in 12.5 ml of the solution. The molarity of the HCl solution is equal to 0.005/0.0125 = 0.4

The molarity of the HCl solution is 0.4 M

lochana2500 | Student, Undergraduate | (Level 1) Valedictorian

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the amount of moles = volume(ml)*molarity*10⁻³

Amout of NaOH moles = 25*0.2*10⁻³ ⇒ ❶

get the molarity of HCl as y

Hence amout of HCl moles = 12.5y*10⁻³ ⇒ ❷

1NaOH + 1HCl → 1NaCl + 1H₂O

❶ = ❷

25*0.2*10⁻³  = 12.5y*10⁻³

25*0.2 = 12.5y

5 = 12.5y

y = 5/12.5

y = 0.4M

therefore the molarity of HCl equals to 0.4M