Answer:
The unknown base should be KOH whose molar mass is 56 g per mol (Answer)
Step-by-step explanation:
Molarity = moles /(Volume in liters)
So,
Moles = Molarity
Volume
![\\$=0.219 M * 289 m L$\\\\$=0.219 (m o l)/(L) * 0.289 L$\\\\$=0.063291 \mathrm{mol}$](https://img.qammunity.org/2020/formulas/chemistry/middle-school/1fb07nd365pw0wwplj4wo48ir2gk7r7c4j.png)
Molar mass = mass/moles
![\\\\$=\frac{3.50 \mathrm{g}}{0.063291 \mathrm{mol}}=55.3 \mathrm{g}$ per mole](https://img.qammunity.org/2020/formulas/chemistry/middle-school/ffx0bes85yuasmufi9s617fkzogd7ye7bt.png)
The unknown base should be KOH whose molar mass is 56 g per mol (Answer)