Respuesta :
Answer:
21 mL of KOH
Explanation:
We have to start with the reaction between HCl and KOH:
[tex]HCl~+~KOH->~KCl~+~H_2O[/tex]
Now, using the molarity equation we can find the moles of HCl, (we have to keep in mind that we have to use the volume in L, 21 mL=0.021 L)
[tex]M=\frac{#~mol}{L}[/tex]
[tex]0.1~M=\frac{#~mol}{0.021~L}[/tex]
[tex]#~mol=0.1~M*0.021~L[/tex]
[tex]#~mol=0.0021[/tex]
Now, we can convert from mol of HCl to mol of KOH using the molar ratio of the balanced reaction. (1 mol HCl= 1 mol KOH)
[tex]0.0021~mol~HCl\frac{1~mol~KOH}{1~mol~HCl}[/tex]
[tex]0.0021~mol~KOH[/tex]
Finally, we have to calculate the volume of KOH using the molarity equation again:
[tex]M=\frac{#~mol}{L}[/tex]
[tex]0.1~M=\frac{0.0021~mol}{L}[/tex]
[tex]L=\frac{0.0021~mol}{0.1~M}[/tex]
[tex]L=0.021~L[/tex]
When we convert this value to mL units we will get:
[tex]0.021~L\frac{1000~mL}{1~L}[/tex]
[tex]21~mL[/tex]
We will need 21 mL of KOH at the equivalence point.
Titration is the determination of the concentration of an unknown solution by the known solution. The volume of the added base is 21 mL.
What is Volume?
Volume in the titration process is given by the molar concentration. The volume of the solution is the ratio of the moles of the substance and that of the molar concentration.
The reaction between hydrochloric acid and potassium hydroxide is given as:
[tex]\rm HCl + KOH \rightarrow KCl + H_{2}O[/tex]
Moles of hydrochloric acid can be estimated by the molarity equation as:
[tex]\begin{aligned}\rm Molarity &= \rm \dfrac{moles}{Volume}\\\\&= 0.1\times 0.021\\\\&= 0.0021\;\rm mol\end{aligned}[/tex]
The volume of potassium hydroxide can be calculated by the molarity equation as:
[tex]\begin{aligned}\rm Molarity &=\rm \dfrac{moles}{Volume}\\\\&= \dfrac{0.0021}{0.1}\\\\&= 0.021\;\rm L\end{aligned}[/tex]
Therefore, 21 mL of KOH is required.
Learn more about the molarity equation here:
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