Calculate the solid needed to make a 250ml solution that is 0.34M in sodium cation, using sodium sulfate decahydrate. I came up with 13.685g. but how do I make that into 250ml of a solution that is0.34M in sodium cation?
There are two sodiums per molecule, so divide that mass you got (I didn't check it), by 2 to get the concentration of the Sodium cation
To calculate the amount of sodium sulfate decahydrate needed to prepare a 250 ml solution that is 0.34 M in sodium cation, you need to follow these steps:
Step 1: Determine the molar mass of sodium sulfate decahydrate (Na2SO4ยท10H2O).
- The molar mass of sodium (Na) is 22.99 g/mol.
- The molar mass of sulfur (S) is 32.07 g/mol.
- The molar mass of oxygen (O) is 16.00 g/mol.
- The molar mass of hydrogen (H) is 1.01 g/mol.
- So, the molar mass of sodium sulfate decahydrate is:
(2 * 22.99 g/mol) + 32.07 g/mol + (4 * 16.00 g/mol) + (10 * [(2 * 1.01 g/mol) + (16.00 g/mol)]) = 322.20 g/mol
Step 2: Calculate the amount of sodium sulfate decahydrate needed (in grams) using the molarity and volume of the solution.
- The molarity (M) of a solution is defined as moles of solute divided by the volume of the solution in liters.
- The molar concentration (C) of sodium cation (Na+) will be 0.34 M.
- The volume (V) of the solution is 250 ml, which is equal to 0.25 L.
- The moles of sodium cation (Na+) needed can be calculated using the formula: Molarity (M) = moles (mol) / volume (L).
- Rearranging the formula gives: moles (mol) = Molarity (M) * volume (L).
- Substitute the given values: moles (mol) = 0.34 M * 0.25 L = 0.085 mol
- Now, use the moles and molar mass to find the mass of sodium sulfate decahydrate.
- mass (g) = moles (mol) * molar mass (g/mol) = 0.085 mol * 322.20 g/mol = 27.408 g
Therefore, you will need approximately 27.408 grams of sodium sulfate decahydrate to prepare a 250 ml solution that is 0.34 M in sodium cation.
To calculate the amount of solid needed to make a solution, you can follow these steps:
Step 1: Determine the molecular weight of sodium sulfate decahydrate.
The molecular weight of sodium sulfate decahydrate can be calculated using the atomic masses of its elements: Sodium (Na) has a molar mass of 22.99 g/mol, sulfur (S) has a molar mass of 32.07 g/mol, oxygen (O) has a molar mass of 16.00 g/mol, and water (H2O) has a molar mass of 18.02 g/mol.
The molar mass of sodium sulfate decahydrate can be calculated as follows:
(22.99 g/mol Na + 32.07 g/mol S + 4 * 16.00 g/mol O) + 10 * (18.02 g/mol H2O) = 322.20 g/mol
Step 2: Calculate the number of moles of sodium sulfate decahydrate needed.
To achieve a 0.34M concentration of sodium cation in a 250 ml solution, you first need to calculate the number of moles required.
0.34 M concentration means 0.34 moles per liter (mol/L).
Given that the volume of the solution is 250 ml, it needs to be converted to liters by dividing by 1000:
250 ml / 1000 ml/L = 0.25 L
To calculate the number of moles, use the formula:
Moles = Concentration (M) * Volume (L)
Moles = 0.34 mol/L * 0.25 L = 0.085 moles
Step 3: Convert moles to grams.
To convert moles to grams, multiply the number of moles by the molar mass of sodium sulfate decahydrate:
0.085 moles * 322.20 g/mol = 27.387 g
Therefore, you would need approximately 27.387 grams of sodium sulfate decahydrate to make a 250 ml solution that is 0.34 M in sodium cation. Keep in mind that this is a rough calculation and you may need to adjust the amount of solid based on the actual concentration of the stock solution you have.