Calculate the concentration (M) of arsenic acid (H3AsO4) in a solution if 25.00 mL of that solution required 35.21 mL of 0.1894 M KOH for neutralization.

Respuesta :

Answer:

[tex]M_{acid}=0.08892M[/tex]

Explanation:

Hello!

In this case, since the reaction between arsenic acid and potassium hydroxide is:

[tex]H_3AsO_4+3KOH\rightarrow K_3AsO_4+3H_2O[/tex]

Thus, since the mole ratio between the acid and the base is 1:3, at the equivalence point we can write:

[tex]3n_{acid}=n_{base}[/tex]

That in terms of molarities and volumes is:

[tex]3M_{acid}V_{acid}=M_{base}V_{base}[/tex]

Thus, the concentration of the arsenic acid is:

[tex]M_{acid}=\frac{M_{base}V_{base}}{3V_{acid}}=\frac{0.1894M*35.21mL}{3*25.00mL} \\\\M_{acid}=0.08892M[/tex]

Best regards!

The concentration (M) of arsenic acid in a solution of 25.00 mL is 0.088M.

How we calculate the molarity?

Molarity of any solution will be calculated as:

M = n/V, where

V = volume

n is the moles and it will be calculated as:
n = W/M, where

W = given mass

M = molar mass

Given chemical reaction is:

H₃AsO₄ + 3KOH → K₃AsO₄ + 3H₂O

Moles of 35.21 mL of 0.1894 M KOH will be calculated as:

n = (0.1894)(0.035) = 0.0066 moles

From the stoichiometry of the reaction it is clear that:

1 mole of H₃AsO₄ = react with 3 moles of KOH

0.0066 moles of KOH = react with 1/3×0.0066= 0.0022 moles of H₃AsO₄

Now we calculate the molarity of H₃AsO₄ in 25mL of solution as:

M = 0.0022/0.025 = 0.088 M

Hence, required molarity is 0.088 M.

To know more about molarity, visit the below link:

https://brainly.com/question/26873446