Calculate the mass of solid neded to make 500ml of solution that is 0.25m in sulfate ion, using sodium sulfate decahydrate.
I ASSUME that is 0.25M and not 0.25m. M means molarity. m means molality.
How many moles do you need? That will be M x L = 0.500 x 0.25M = ?
moles Na2SO4.10H2O = grams/molar mass.
40
To calculate the mass of solid needed to make 500ml of a 0.25m solution of sulfate ion using sodium sulfate decahydrate, follow these steps:
Step 1: Determine the molar mass of sodium sulfate decahydrate:
The formula of sodium sulfate decahydrate is Na2SO4･10H2O.
The molar mass of Na2SO4 is:
2(Na) + (S) + 4(O) = 2(22.99 g/mol) + 32.06 g/mol + 4(16.00 g/mol) = 142.04 g/mol
The molar mass of H2O is:
10(H) + 2(O) = 10(1.01 g/mol) + 2(16.00 g/mol) = 180.18 g/mol
Therefore, the molar mass of sodium sulfate decahydrate is:
142.04 g/mol + 180.18 g/mol = 322.22 g/mol
Step 2: Calculate the moles of sulfate ion required:
To make a 0.25m solution, we need 0.25 moles of sulfate ion per liter of solution.
Since we have 500ml (or 0.5L) of solution, the moles of sulfate ion needed is:
0.25 mol/L × 0.5 L = 0.125 mol
Step 3: Calculate the mass of sodium sulfate decahydrate required:
To find the mass, we can use the formula:
mass = moles × molar mass
The mass of sodium sulfate decahydrate required is:
0.125 mol × 322.22 g/mol = 40.28 g
Therefore, you would need approximately 40.28 grams of sodium sulfate decahydrate to make 500ml of a 0.25m solution of sulfate ion.
To calculate the mass of solid needed to make the solution, we need to use the molarity and the volume of the solution.
First, let's determine the moles of sulfate ion (SO4^2-) needed in the solution:
Molarity (M) is defined as moles of solute per liter of solution.
Given:
Molarity (M) = 0.25 M
Volume (V) = 500 mL = 0.5 L (converted from milliliters to liters)
Using the formula: M = moles/volume, we can rearrange it to solve for moles:
moles = M x volume
moles of sulfate ion = 0.25 M x 0.5 L
moles of sulfate ion = 0.125 moles
Now, we need to find the molar mass of sodium sulfate decahydrate (Na2SO4 · 10H2O) in order to convert moles to grams:
Molar mass of sodium sulfate (Na2SO4) = 22.99 g/mol (sodium) + 32.07 g/mol (sulfur) + (4 × 16.00 g/mol) (oxygen)
Molar mass of sodium sulfate = 142.04 g/mol
Molar mass of water (H2O) = 2 × 1.01 g/mol (hydrogen) + 16.00 g/mol (oxygen)
Molar mass of water = 18.02 g/mol
Molar mass of sodium sulfate decahydrate = (2 × 22.99 g/mol) + 32.07 g/mol + (4 × 16.00 g/mol) + (10 × 18.02 g/mol)
Molar mass of sodium sulfate decahydrate = 322.20 g/mol
Now, we can calculate the mass of sodium sulfate decahydrate needed:
mass = moles × molar mass
mass = 0.125 moles × 322.20 g/mol
Therefore, the mass of sodium sulfate decahydrate needed to make 500 mL of a 0.25 M sulfate ion solution is approximately 40.275 grams.