Question #f9045

1 Answer
Jul 24, 2015

Answer:

You'd neeed 35.3 mL.

Explanation:

Start by writing the balanced chemical equation for this neutralization reaction

#HI_((aq)) + KOH_((aq)) -> KI_((aq)) + H_2O_((l))#

The important thing to notice here is that you ahve a #1:1# mole ratio between hydroiodic acid and potassium hydroxide.

This means that, in order to have a complete neutralization, you need equal numbers of moles of each compound.

SInce you know the molarity and volume of the potassium hydroxide solution, you can determine how many moles of #KOH# took part in the reaction

#C = n/V => n = C * V#

#n_(KOH) = "0.171 M" * 27.9 * 10^(-3)"L" = "0.004771 moles"# #KOH#

This means that you also had

#0.004771cancel("moles"KOH) * ("1 mole "HI)/(1cancel("mole"KOH)) = "0.004771 moles"# #HI#

Now simply use the hydroiodic acid solution's molarity to see what volume would contain this many moles

#C = n/V => V = n/C#

#V_(HI) = (0.004771cancel("moles"))/(0.135cancel("moles")/"L") = "0.0353 L"#

Expressed in mililiters, the answer will be

#V_(HI) = color(green)("35.3 mL")#