A chemist makes a solution of K2SO4 by dissolving 21.7 g K2SO4 in water to make 100.0 mL of solution. What is the concentration of SO42− ions in the solution? Assume that K2SO4 is the only solute in the solution. The molar mass of K2SO4 is 174.27 g/mol.

Question

A chemist makes a solution of K2SO4 by dissolving 21.7 g K2SO4 in water to make 100.0 mL of solution. What is the concentration of SO42− ions in the solution? Assume that K2SO4 is the only solute in the solution. The molar mass of K2SO4 is 174.27 g/mol.

Answer 1

To find the concentration of SO42- ions in the solution, we need to first calculate the number of moles of K2SO4.

First, let's calculate the number of moles of K2SO4:
Number of moles = mass / molar mass

Number of moles of K2SO4 = 21.7 g / 174.27 g/mol = 0.1245 mol

Next, we need to calculate the total volume of the solution in liters:
Total volume = 100.0 mL = 100.0 mL / 1000 mL/L = 0.100 L

Since K2SO4 dissociates into two K+ ions and one SO42- ion, the number of moles of SO42- ions is the same as the number of moles of K2SO4.
Number of moles of SO42- ions = 0.1245 mol

Finally, we can calculate the concentration of SO42- ions in the solution:
Concentration = Number of moles / Total volume

Concentration of SO42- ions = 0.1245 mol / 0.100 L = 1.245 M

Therefore, the concentration of SO42- ions in the solution is 1.245 M.

Answer 2

To find the concentration of SO42- ions in the solution, we need to calculate the number of moles of K2SO4 and then use stoichiometry to determine the number of moles of SO42- ions.

Step 1: Calculate the number of moles of K2SO4.
The molar mass of K2SO4 is 174.27 g/mol.
Given that the mass of K2SO4 is 21.7 g, we can use the formula: moles = mass / molar mass.

moles of K2SO4 = 21.7 g / 174.27 g/mol

Step 2: Calculate the number of moles of SO42- ions.
In K2SO4, there are two K+ ions and one SO42- ion.
This means that there are the same number of moles of K2SO4 and SO42- ions.

moles of SO42- ions = moles of K2SO4

Step 3: Calculate the volume of the solution in liters.
Given that the volume is 100.0 mL, we need to convert it to liters.
1 L = 1000 mL, so 100.0 mL = 100.0 / 1000 = 0.1 L

Step 4: Calculate the concentration of SO42- ions.
Concentration is defined as moles of solute per liter of solution.
Concentration of SO42- ions = moles of SO42- ions / volume of solution

Concentration of SO42- ions = moles of SO42- ions / 0.1 L

Now you have all the information needed to calculate the concentration of SO42- ions.

Answer 3

mols K2SO4 = grams/molar mass = ?

mols [SO4]^2- = mols K2SO4 since there is 1 mols SO4 in 1 mol K2SO4.
L = 100 mL = 0.100 L
Then M = mols/L