Answer to Question #342198 in General Chemistry for Rob

Question

What volume of 0.100 M K2S solution contains 3.5 g of the solute?

Answer 1

1. From the formula C_M = n / V we derive the formula for finding V (volume):

V = n / C_M .

V– volume

n– amount of substance ( mol )

C_M– concentration molarity

2. We find the amount of substance (n). To do this, we divide the mass of K₂S (110g/mol) by its molecular mass:

n=m/M = 3.5 / 110 = 0.03182 mol

3. We find the volume using the formula V=n/C_M:

V = n / C_M = 0.03182 / 0.1 = 0.3182 litr.

ANSWER: 0.3182 litr or 318.2 ml