Question

Calculate the molarity of a solution made by adding 150.0 mL of water to 85.00 mL of a 0.157 M solution.

How many milliliters of a 0.180 M KCl solution are needed to provide 0.0306 mol KCl?

If the red dye #40 concentration is 3.00×10^-3 M in the original syrup, what is its concentration in dilution #3 (enter your answer in the box below the image)? The red dye #40 syrup is diluted by a factor of 2 three times.

Which 0.500 M solution will be the least conductive? Choose all that apply.
A. Acetic acidB. Methanol C. Dextrose (table sugar) D. Sodium chloride

Answer 1

Ans 1 :

Using the formula M1V1 = M2V2

putting values :

0.157 x 85.00 = M2 x 150.0

M2 = 0.0889 M

So the moalrity will be 0.0889 M

Ans 2 :

Molarity = number of moles / volume of solution in L

0.180 = 0.0306 / V

V = 0.17 L

= 170 mL

Ans 3 :

dilution factor is 2

SO after the first dilution , the moalrity becomes half = (3.00 x 10^-3) /2 = 1.5 x 10^-3 M

After second dilution = (1.5 x 10^-3) / 2 = 0.75 x 10^-3 M

final moalrity after third dilution = ( 0.75 x 10^-3) / 2

= 3.75 x 10^-4 M

Ans 4 : C) Dextrose

The compounds that are molecular and have covalent bonds in between their constituent atoms are least conductive.The ionic compounds dissociate into their ions in the solution and hence conduct electricity.