Answer:
0.1 M
Explanation:
Molarity = number of moles / litres of solution.
4 g of calcium bromide = 0.02 mol
(found by dividing 4 g by the atomic mass of CaBr2, which is 199.886)
200 mL of solution = 0.2 litres
Molarity = 0.02 mol / 0.2 L = 0.1 M
Taking into account the definition of molarity, the molarity of the solution is 0.1 [tex]\frac{moles}{L}[/tex].
In first place, you have to know that molarity is a measure of the concentration of that substance and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
[tex]Molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{L}[/tex].
In this case you know that 4.0 g of calcium bromide, CaBr₂, dissolves in enough water. Then, the molar mass of calcium bromide being 199.8 g/mole, (that is, the mass of one mole of the compound), the number of moles that 4.0 g of the compound contain is calculated as:
amount of moles=4.0 g × [tex]\frac{1 mole}{199.8g}[/tex]
amount of moles= 0.02 moles
And being the volume 200 mL = 0.2 L (being 1000 mL= 1 L), and replacing the values in the definition of molarity, you obtain:
[tex]Molarity=\frac{0.02 moles}{0.2 L}[/tex]
Solving:
Molarity= 0.1 [tex]\frac{moles}{L}[/tex]
In summary, the molarity of the solution is 0.1 [tex]\frac{moles}{L}[/tex].
Learn more about molarity with this example: brainly.com/question/15406534?referrer=searchResults
