Question

A chemist is performing a titration in order to determine the amount of lithium hydroxide, LiOH(aq), in 125 mL of an aqueous solution. (a) If 27 mL of a 0.17 M HCl solution was used as a titrant to reach the equivalence point, what was the concentration of lithium hydroxide in the initial solution? M (b) What was the initial pH of the lithium hydroxide solution?

Answer 1

To determine the concentration of lithium hydroxide in the initial solution, use a 0.17 M HCl solution as a titrant and measure the volume needed to reach the equivalence point. Calculate the initial pH by subtracting the pOH from 14.

Step-by-step explanation:

In this titration, a chemist is determining the concentration of lithium hydroxide (LiOH) in an aqueous solution. To do this, they use a 0.17 M HCl solution as a titrant and measure the volume needed to reach the equivalence point.

To find the concentration of the lithium hydroxide in the initial solution, we can use the equation:

M1V1 = M2V2

where M1 is the initial concentration, V1 is the initial volume, M2 is the final concentration (the concentration of HCl in this case), and V2 is the final volume (the volume of HCl used to reach the equivalence point).

Using the given values, we have:

(M1)(125 mL) = (0.17 M)(27 mL)

From this equation, we can solve for M1 (the initial concentration).

(b) To find the initial pH of the lithium hydroxide solution, we need to calculate the concentration of hydroxide ions (OH-) in the solution. This can be done using the equation:

pOH = -log[OH-]

Since pOH + pH = 14 for aqueous solutions at 25°C, we can then calculate the initial pH by subtracting the pOH from 14.