Determine the chloride ion concentration in a solution containing 50.0 g MgCl2 dissolved in 1500 mL of solution.
a. 0.350 M
b. 0.700 M
c. 1.40 M
d. 3.17 M
e. 6.34 M
50g of MgCl2 is how many moles.
Then, there are two chloride ions per molecule, so double the number of moles.
Molarity= moles of chloride ions/1.5
0.700
To determine the chloride ion concentration in the solution, we need to first calculate the number of moles of MgCl2, and then divide it by the volume of the solution in liters.
Step 1: Calculate the number of moles of MgCl2.
Given:
Mass of MgCl2 = 50.0 g
Molar mass of MgCl2 = 95.211 g/mol (24.305 g/mol for Mg + 2 * 35.453 g/mol for Cl)
Number of moles of MgCl2 = Mass of MgCl2 / Molar mass of MgCl2
Number of moles of MgCl2 = 50.0 g / 95.211 g/mol = 0.5258 mol
Step 2: Convert the volume of the solution to liters.
Given:
Volume of solution = 1500 mL
Volume of solution in liters = 1500 mL / 1000 mL/L = 1.5 L
Step 3: Calculate the chloride ion concentration.
Chloride ion concentration (M) = Number of moles of MgCl2 / Volume of solution (L)
Chloride ion concentration (M) = 0.5258 mol / 1.5 L ≈ 0.350 M
Therefore, the chloride ion concentration in the solution is approximately 0.350 M. The correct answer is option a. 0.350 M.
To determine the chloride ion concentration in the solution, we need to calculate the molarity (M) of MgCl2 and then multiply it by the number of chloride ions per molecule of MgCl2.
First, let's calculate the molarity (M) of MgCl2:
Molarity (M) = moles of solute / liters of solution
To find the moles of MgCl2, we need to divide the given mass of MgCl2 by its molar mass. The molar mass of MgCl2 can be calculated by adding the atomic masses of magnesium (Mg) and two chlorine (Cl) atoms.
The atomic mass of Mg = 24.31 g/mol
The atomic mass of Cl = 35.45 g/mol
Molar mass of MgCl2 = 24.31 + (2 * 35.45) = 95.21 g/mol
Now, we can calculate the moles of MgCl2:
moles of MgCl2 = mass of MgCl2 / molar mass of MgCl2
mass of MgCl2 = 50.0 g
moles of MgCl2 = 50.0 g / 95.21 g/mol
Next, we need to convert the given volume of the solution from milliliters (mL) to liters (L):
volume of solution = 1500 mL = 1500 mL / 1000 mL/L = 1.5 L
Now, we can calculate the molarity (M) of MgCl2:
Molarity of MgCl2 = moles of MgCl2 / volume of solution
Now, to determine the chloride ion (Cl-) concentration, we need to multiply the molarity of MgCl2 by the number of chloride ions per molecule of MgCl2. In MgCl2, there are two chloride ions.
Chloride ion concentration = Molarity of MgCl2 x 2
Now, let's calculate the chloride ion concentration:
Molarity of MgCl2 = (50.0 g / 95.21 g/mol) / 1.5 L = 0.3498 M
Chloride ion concentration = 0.3498 M x 2 = 0.6996 M
Rounding to three significant figures, the chloride ion concentration is approximately 0.700 M.
Therefore, the correct answer is b. 0.700 M.