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Consider five solutions that all have the same mass of solute in 100.0 mL of solution. Which has the highest concentration as measured in molarity

User Ed Norris
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1 Answer

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Answer:

d

Step-by-step explanation:

a. KCl

b. NaCl

c. Na2SO4

d. NaF

e. CaCl2

The molarity of a solution is a measure of the number of moles of solutes per volume (in liters) of the solution.

The number of moles of a solute depends largely on the mass and the molar mass of the solute. Hence,

mole = mass/molar mass

Equal amounts of KCl, NaCl, Na2SO4, NaF, and CaCl2 would have a different number of moles due to a difference in their molar mass. The higher the molar mass, the lower the number of moles, and vice versa.

The molar mass (in g/mole) of each of the solute compounds is as follows

KCl - 74.55

NaCl - 58.44

Na2SO4 - 142.04

NaF - 41.99

CaCl2 - 110.98

NaF has the lowest molar mass and, hence, would have the highest number of moles. This means that when an equal amount of the substances above is dissolved in the same amount of water, NaF would have the highest molarity.

The correct option is d.

User Camnesia
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