6.4 ml of 0.625 m hydroiodic acid is added to 31.0 ml of barium hydroxide, and the resulting solution is found to be acidic. 27.9 ml of 0.760 m potassium hydroxide is required to reach neutrality. what is the molarity of the original barium hydroxide solution?

Molarity of Ba(OH)₂ is 0.227 M

Explanation:

We are given;

At this point, we can determine the original number of moles of HCl and also write the equation between HCl and Ba(OH)₂.

Moles = Volume × Molarity

Therefore;

Moles of HCl given = 0.625 M × 0.0564 L

                               = 0.03525 moles

The equation for the reaction is;

Equation 1:

2HCl + Ba(OH)₂ → BaCl₂ + 2H₂O

Therefore;

We can determine the moles of KOH that reacted with excess HCl and also write the equation for the reaction.

Moles = Molarity  × volume

Molarity of KOH = 0.760 M × 0.0279 L

                          = 0.0212 moles

The equation for the reaction between HCl and KOH

Equation 2:

HCl + KOH → KCl + H₂O

Thus;

Moles of HCl = moles of KOH

Therefore, moles of HCl that reacted with KOH is 0.0212 moles

This means moles of HCl that reacted with Ba(OH)₂ will be given by;

= Original moles of HCl minus moles of HCl that reacted with KOH

= 0.03525 moles - 0.02120 moles

= 0.01405 moles

Thus, Moles of HCl that reacted with Ba(OH)₂ is 0.01405 moles

But,from the first equation;

Mole ratio of HCl to Ba(OH)₂ is 2 : 1

Thus;

Moles of Ba(OH)₂ = Moles of HCl ÷ 2

                             = 0.01405 moles ÷ 2

                             = 0.007025 moles

But, Molarity = Moles ÷ Volume

Molarity of Ba(OH)₂ = 0.007025 moles ÷ 0.031 L

                                = 0.227 M

Thus, the molarity of Ba(OH)₂ is 0.227 M

c.

explanation:

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.