Atitration was performed on 50.0ml of 0.250 m naoh.after the
addition of 7.14ml of hci, the phenolpthalein indicatorchanged from
pink to colorless. what was the concentration ofthe hydrochloric
acid?

1.750 M

Explanation:

In case of titration , the following formula can be used -

M₁V₁ = M₂V₂

where ,

M₁ = concentration of acid ,

V₁ = volume of acid ,

M₂ = concentration of base,

V₂ = volume of base .

from , the question ,

M₁ = ? M

V₁ = 7.14 mL

M₂ = 0.250 M

V₂ = 50 mL

Using the above formula , the molarity of acid , can be calculated as ,

M₁V₁ = M₂V₂

M₁ * 7.14 mL = 0.250 M * 50mL

M₁ = 1.750 M

Hence, the molarity of the hydrochloric acid = 1.750 M

Yet both compounds and elements are considered pure substances. Pure compounds are created when elements combine permanently, forming one substance. For example, when the elements mercury and oxygen combine, and a chemical reaction takes place, mercury (II) oxide is created.

Hope this helps!