Question

Prepare the following solutions by determiing the proper mass of solute (or volume in the case where you are working from a stock solution) that will need to be transferred to the volumetric flask. Use diemensional analysis where apporpriate to do so. Describe how you would make each solution.

a. 150.0 mL of .50 M hydrochorlic acid solution from a concetrated stock solution of 12.0M hydrochloric acid.

b. 250.0 mL of a 1.50 M solution of potassium permanganate.

c. 2.00 L of a 3.0 Molar solution of perchloric acid from a 5.0M stock solution of perchloric acid.

d. 500.0 mL of a .300 molar solution of calcium hydroxide.

Answer 1

Solution A :

we just need to equate the equivalent of the two solution and we will get the desired result of the solution

150ml * 0.5M *1 = Vml * 12M * 1

= 6.25ml = Vml (12M solution volume required)

Solution B :

Mass of Potassium permanganate

Molarity = moles / volume

= 0.250*1.50 = moles of potassium permangante

= 0.375 = Mass/ 158

= 59.25 grams = Mass

Solution C

Equationg the equivalents again

= 2*3 = 5*Vml

= 1.2 L = Volume of stock solution of perchloric acid

Solution D

Mass of Calcium Hydroxide

= Molarity = moles / volume

= 0.5*.30 = moles of Calcium hydroxide

= 0.15 = mass / molecular mass

= 0.15*74 = Mass

= 11.1 grams = Mass Of CaOH2