Answer:
2.50M
Explanation:
Concentration of a solution describes how much of a solute is dissolved in a solvent in a solution. Molarity of a solution is one way to calculate the concentration of a solution.
The Molarity, M is calculated using the formula: number of moles (n) / volume of solution (litres).
To calculate, the number of moles (n), we say that number of moles = mass of solute / molar mass
In this case, CaBr2 (Calcium Bromide) solution is used where mass no of Calcium (Ca) is 40g/mol and Bromine (Br) is 79.9g/mol
Molar mass of CaBr2= 40 + 79.9(2)
40 + 159.8 = 199.8
Hence, molar mass of CaBr2 is 199.8g/mol
Mass of solute= 125grams
Number of moles (n) of CaBr2 = 125/199.8 = 0.6256
n = 0.6256moles
Volume of CaBr2 solution is 250millilitres(ml). Since, 1000ml= 1L, then 250ml is 250/1000 L
= 0.25L
Molarity of solution (M) = number of moles (n)/ volume of solution (litres)
M = 0.6256/0.25
M= 2.5
Thus, the molarity (concentration) of the solution is 2.5M