1. Write the balanced chemical equation:

HNO₃ (aq) + LiOH (aq) → LiNO₃ (aq) + H₂O (l)

2. Determine the moles of HNO₃:

* Molarity (M) = moles (mol) / volume (L)

* Rearrange to solve for moles: moles = M * V

* Convert the volume of HNO₃ from mL to L: 81.7 mL * (1 L / 1000 mL) = 0.0817 L

* Calculate the moles of HNO₃: 1.34 M * 0.0817 L = 0.1096 mol HNO₃

3. Use the mole ratio from the balanced equation:

* The balanced equation shows a 1:1 mole ratio between HNO₃ and LiOH. This means that 0.1096 mol of HNO₃ reacted with 0.1096 mol of LiOH.

4. Calculate the concentration of LiOH:

* Concentration (M) = moles (mol) / volume (L)

* Convert the volume of LiOH from mL to L: 56.3 mL * (1 L / 1000 mL) = 0.0563 L

* Calculate the concentration of LiOH: 0.1096 mol / 0.0563 L = 1.95 M

Therefore, the concentration of the lithium hydroxide solution is 1.95 M.