A solution is prepared by dissolving 25.0 g of ammonium sulfate in enough water to make 100.0 mL of stock solution. A 10.0 mL sample of this stock solution is added to50.0 mL of water. Calculate the concentration of ammonium ions and sulfate ions in the final solution.
a chemist pours 20 grams of a liquid into a beaker. what is the volume of the liquid if it has a density of 2.5 grams/ml.
25 g (NH4)2SO4 in 100 mL soln.
Dilute 10 mL to 50 mL.
Concn is not 25 g x (10/50) = 5.0 g in the 50
moles (NH4)2SO4 = grams/molar mass
M = moles/L. (note: L is 0.050 from the 50 mL)
(SO4^-2) = [(NH4)2SO4]
(NH4^+) = 2 x [(NH4)2SO4]
To calculate the concentration of ammonium ions and sulfate ions in the final solution, we need to determine the amount of these ions present in the stock solution and the final volume of the solution.
1. Calculate the amount of ammonium sulfate in the stock solution:
The amount of ammonium sulfate = mass / molar mass
The molar mass of ammonium sulfate (NH4)2SO4 is 132.14 g/mol.
Therefore, the amount of ammonium sulfate = 25.0 g / 132.14 g/mol = 0.1892 mol
2. Calculate the amount of ammonium ions in the stock solution:
Since the formula of ammonium sulfate is (NH4)2SO4, there are 2 moles of ammonium ions (NH4+) for every mole of ammonium sulfate.
Therefore, the amount of ammonium ions = 2 * 0.1892 mol = 0.3784 mol
3. Calculate the concentration of ammonium ions in the final solution:
The final volume of the solution = volume of stock solution + volume of water = 10.0 mL + 50.0 mL = 60.0 mL = 0.0600 L
Concentration of ammonium ions = amount of ammonium ions / final volume of the solution
= 0.3784 mol / 0.0600 L = 6.307 M
4. Calculate the amount of sulfate ions in the stock solution:
Since the formula of ammonium sulfate is (NH4)2SO4, there is 1 mole of sulfate ions (SO4^2-) for every mole of ammonium sulfate.
Therefore, the amount of sulfate ions = 1 * 0.1892 mol = 0.1892 mol
5. Calculate the concentration of sulfate ions in the final solution:
Concentration of sulfate ions = amount of sulfate ions / final volume of the solution
= 0.1892 mol / 0.0600 L = 3.153 M
Therefore, the concentration of ammonium ions in the final solution is 6.307 M and the concentration of sulfate ions is 3.153 M.
To calculate the concentration of ammonium ions and sulfate ions in the final solution, we first need to find the amount of ammonium sulfate in the stock solution and the amount of water added.
1. Calculation of the moles of ammonium sulfate:
The molar mass of ammonium sulfate (NH4)2SO4 is:
(2 x 14.01 g/mol) + (4 x 1.01 g/mol) + 32.06 g/mol = 132.14 g/mol
Given that the mass of ammonium sulfate is 25.0 g, we can use the formula:
moles = mass / molar mass
moles of ammonium sulfate = 25.0 g / 132.14 g/mol
2. Calculation of the concentration of ammonium ions and sulfate ions in the stock solution:
The volume of the stock solution is 100.0 mL. Since moles = concentration x volume, we can rearrange the equation to calculate the concentration:
concentration = moles / volume
concentration of ammonium ions = moles of ammonium sulfate / volume of stock solution
concentration of ammonium ions = (25.0 g / 132.14 g/mol) / 100.0 mL
Repeat the same process to calculate the concentration of sulfate ions.
3. Calculation of the concentration in the final solution:
To find the concentration in the final solution, we need to consider the dilution that occurred when the 10.0 mL sample of the stock solution was added to 50.0 mL of water.
Using the equation:
concentration1 x volume1 = concentration2 x volume2
Let concentration1 be the concentration of the stock solution (ammonium and sulfate ions) and volume1 be the volume of the stock solution.
Let concentration2 be the concentration in the final solution (ammonium and sulfate ions) and volume2 be the volume of the final solution.
volume1 = 10.0 mL (stock solution)
volume2 = 10.0 mL (stock solution) + 50.0 mL (water) = 60.0 mL (final solution)
Now we can solve for concentration2.
Once you have the value of concentration2, you can find the individual concentrations of ammonium ions and sulfate ions by multiplying the concentration2 value by their respective stoichiometric coefficients.
Please note that it is important to consider the units when performing calculations and ensure that all values are in the same units (grams, moles, or milliliters).