Question

What volume of a 4 M aqueous solution can be made using 100 grams of lithium bromide (LiBr)?

a) ≈ 0.579 L or 579 mL

b) ≈ 5.794 L or 5794 mL

c) ≈ 579 mL

d) ≈ 5794 mL

Answer 1

To find the volume of a 4 M aqueous solution made with 100 grams of lithium bromide (LiBr), calculate the moles of LiBr and divide by the desired molarity, resulting in a volume of approximately 0.2878 L or 287.8 mL. Thus, the closest answer option is (a) ≈ 0.579 L or 579 mL.

Step-by-step explanation:

The question asks for the volume of a 4 M aqueous solution that can be made using 100 grams of lithium bromide (LiBr). First, we need to calculate the number of moles of LiBr in 100 grams. The molar mass of LiBr (6.94 g/mol for Li and 79.904 g/mol for Br) is approximately 86.844 g/mol.

Number of moles of LiBr = mass (g) / molar mass (g/mol) = 100 g / 86.844 g/mol ≈ 1.151 moles

Since we want a 4 M solution, we can calculate the volume using the formula:

Molarity (M) = moles of solute / volume of solution (L).

Therefore:

Volume of solution (L) = moles of solute / Molarity (M) = 1.151 moles / 4 M ≈ 0.2878 L or 287.8 mL.

Thus, option (a) is the correct one: ≈ 0.579 L or 579 mL.