Answer:
![M_(base)=0.709M](https://img.qammunity.org/2021/formulas/chemistry/college/6boqah1h1zz50o97fn6768t7z0xverp2zz.png)
Step-by-step explanation:
Hello,
In this case, since the reaction between potassium hydroxide and nitric acid is:
![KOH+HNO_3\rightarrow KNO_3+H_2O](https://img.qammunity.org/2021/formulas/chemistry/high-school/1i9dmqlr3kf7xmef9ogciop6mdhjeckjgf.png)
We can see a 1:1 mole ratio between the acid and base, therefore, for the titration analysis, we find the following equality at the equivalence point:
![n_(acid)=n_(base)](https://img.qammunity.org/2021/formulas/chemistry/high-school/c497c57zrzdor879cbf4fk4lkq1qvciqsi.png)
That in terms of molarities and volumes is:
![M_(acid)V_(acid)=M_(base)V_(base)](https://img.qammunity.org/2021/formulas/chemistry/high-school/1ui9demeahr6k992l5jslb5aodefwas2xe.png)
Thus, solving the molarity of the base (KOH), we obtain:
![M_(base)=(M_(acid)V_(acid))/(V_(base)) =(0.498M*42.7mL)/(30.0mL)\\ \\M_(base)=0.709M](https://img.qammunity.org/2021/formulas/chemistry/college/f4s0iv2xy97jsf38sob1sq1glbqtul4dzl.png)
Regards.