D. CuCl2 copper(2)chloride
Molarity is the molar concentration of the solute dissolved in a volume of a solution. The molarity of the solution prepared by dissolving barium chloride will be 0.085 M.
<h3>What is molarity?</h3>
Molarity is the ratio of the moles of the solute to that of the volume of the solution in Liters. It can be given as,

Here, moles of the barium chloride can be given by the mass and the molar mass and volume is given as 0.450 L.
Substituting values in the equation:

Therefore, 0.085 M barium chloride is the molar concentration.
Learn more about molarity here:
brainly.com/question/26873446
Answer:
b. Add a few drops of one of the layers to a test tube containing 1 mL of water. Shake the test tube to determine the solubility of the layer in water
Explanation:
Option a is not true, it depends on the compound being extracted.
Option c is not true, although most of the solvents used in extractions have lower boiling point than water there are exceptions, for example toluene.
Option d is not true. Again most of the solvents used in extractions are less dense than water, there are many exceptions, for example chloroform, so for equal volumes the chloroform layer will weigh more.
Option b. is the correct one.
One will test the miscibility of the layer in water. If it inmiscible then one would know is the organic layer. If it is the aqueous layer then it will completely be miscible.
The volume of water he dissolved the solute is 250 cubic centimeter.
<u>Explanation</u>:
Concentration = mass of solute in g / volume in dm^3
The concentration of a solution is defined as the ratio of mass of solute in grams to the volume of water in dm^3.
If concentration of a solution = 8 g/dm^3.
mass of solute =2 g.
Volume of a water = 2 / 8 = 0.25 dm^3. (or) 250 cubic centimeter.