High School

A solid sample of Zn(OH)₂ is added to 0.320 L of 0.600 M aqueous HBr. The solution that remains is still acidic. It is then titrated with 0.600 M NaOH solution, and it takes 98.5 mL of the NaOH solution to reach the equivalence point.

What mass of Zn(OH)₂ was added to the HBr solution?

Answer :

Final answer:

The mass of Zn(OH)₂ added can be calculated by determining the moles of NaOH used in the titration. Then, using the stoichiometry of the reaction, find the moles of Zn(OH)₂. Finally, convert moles to grams to find the mass.

Explanation:

First, you would find the moles of NaOH used from the titration. The volume of NaOH solution used was 98.5 mL or 0.0985 L, and since the molarity of the NaOH solution was 0.600 M, you can multiply these values to find that 0.0591 moles of NaOH were used. Then, because the reaction at the equivalence point is Zn(OH)2 + 2NaOH → ZnO2 + 2NaOH, you know that the total moles of Zn(OH)2 is equal to half the moles of NaOH, or 0.02955 moles. Finally, using the molar mass of Zn(OH)2 which is about 99.39g/mol, by multiplying it with the calculated moles of Zn(OH)2 will give us the mass. So the mass of the solid Zn(OH)2 that was added equals 2.94 g.

Learn more about Stoichiometry here:

https://brainly.com/question/34828728

#SPJ11

Other Questions