Question

Calculate the concentration of sulfate in a solution made from 65.0 mL of 0.55 M sodium sulfate and 85.0 mL of 1.25 M iron(III) sulfate?

Answer 1

The concentration of sulfate in the mixed solution is calculated by summing the moles of sulfate from both sodium sulfate and iron(III) sulfate, then dividing by the total volume of the solution. The final concentration of sulfate ion is 0.947 M.

Step-by-step explanation:

Calculation of Sulfate Concentration

To calculate the concentration of sulfate ion in a mixed solution of sodium sulfate and iron(III) sulfate, we first need to determine the number of moles of sulfate ion provided by each solution and then find the total volume of the mixture.

Step 1: Calculate the moles of sulfate from sodium sulfate.

Moles of SO42- = Molarity of Na2SO4 (0.55 M) × Volume of Na2SO4 (0.065 L) = 0.03575 mol

Step 2: Calculate the moles of sulfate from iron(III) sulfate.

Moles of SO42- = Molarity of Fe2(SO4)3 (1.25 M) × Volume of Fe2(SO4)3 (0.085 L) = 0.10625 mol

Step 3: Determine the total moles of sulfate.

Total moles of SO42- = Moles from Na2SO4 + Moles from Fe2(SO4)3 = 0.03575 mol + 0.10625 mol = 0.142 mol

Step 4: Calculate the total volume of the solution.

Total volume = Volume of Na2SO4 + Volume of Fe2(SO4)3 = 0.065 L + 0.085 L = 0.15 L

Step 5: Determine the final concentration of sulfate ion.

Concentration of SO42- = Total moles of SO42- / Total volume = 0.142 mol / 0.15 L = 0.947 M

Answer 2

we are given the molarity and the volume of solution. The only issue is that the volume is given in mL instead of L. This issue can be fixed by using the following conversion factor:

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

a

1000

m

L

=

1

L

Therefore, if we divide 50mL by 1000mL we will obtain a value of 0.05L.

Next, the equation has to be rearranged to solve for the moles of solute:

Moles of solute = Molarity

×

Liters of solution

Now, multiply 0.360 M by 0.05:

0.360 mol

1 L

×

0.05 L

=

0.018 mol

To obtain the mass of solute, we will need to the molar mass of NaCl, which is 58.44 g/mol:

Finally, multiply the number of moles by 58.44 g/mol

0.018

mol

×

58.44

g

1

mol

Boom, here it is:

1.05

g