Chapter 16.3, Problem 2RQ

Interpretation Introduction

Interpretation: The concentration of base needs to be determined.

Concept introduction: At equivalence point of titration,

  $\begin{array}{c}\text{ number of moles of acid}=\text{number of moles of base}\\ M_1{V}_1=M_2{V}_2\end{array}$

• $M_1=$ concentration of the acid.
• $V_1=$ volume of the acid.
• $M_2=$ concentration of the base.
• $V_2=$ volume of the base.

Answer to Problem 2RQ

The concentration of base is $\frac{2.5x}{y}\text{M}$ .

Explanation of Solution

According to the given data,

  $M_1=2.5\text{ M}$

  $V_1=x\text{ mL}$

  $M_2=?$

  $V_2=y\text{ mL}$

  $\begin{array}{c}\left(2.5\text{ M}\right)\times (x\text{ mL)}=\left(M_2\right)\times (y\text{ mL)}\\ {\text{M}}_2=\frac{\left(2.5\text{ M}\right)\times (x\text{ mL)}}{(y\text{ mL)}}\\ =\frac{2.5x}{y}\text{M}\end{array}$

Conclusion

The concentration of base is $\frac{2.5x}{y}\text{M}$ .