what is the concentration in percentage by mass when 0.250 moles of sodium phosphate is dissolved in 300 grams of water
I think you need to convert the moles of sodium phosphate into grams of sodium phosphate. Then use that and divide by 300g of H20. Multiply the number that you get by 100, and it should give you the concentration in percentage mass of sodium phosphate in the ammount of water given 300g.
so,
0.250 mol x 119.98 g/mol= ____g NaH2PO4
Then divide that _____g NaH2PO4 found by 300g of H2O.
______g NaH2PO4 / 300g H2O x 100= ______% by mass concentration.
check me on this of course.
My thoughts on this are as follows:
Na3PO4 = sodium phosphate has a molar mass of 163.941.
0.25 moles x (1 mol Na3PO4/163.941) = 40.985 grams Na3PO4.
%Na3PO4 = (g solute/total mass soln)*100 =
(40.985/40.985+300)*100 =
12 something %. Check my work.
To find the concentration in percentage by mass, you need to calculate the mass of sodium phosphate and the total mass of the solution.
Step 1: Calculate the molar mass of sodium phosphate (Na3PO4):
The molar mass of sodium (Na) is 22.99 g/mol.
The molar mass of phosphorus (P) is 30.97 g/mol.
The molar mass of oxygen (O) is 16.00 g/mol.
Therefore, the molar mass of Na3PO4 is:
(3 * 22.99 g/mol) + 30.97 g/mol + (4 * 16.00 g/mol) = 163.94 g/mol.
Step 2: Calculate the mass of sodium phosphate:
The number of moles (n) of sodium phosphate is given as 0.250 moles.
Using the equation: mass (m) = moles (n) * molar mass (M), the mass of sodium phosphate is:
m = n * M = 0.250 moles * 163.94 g/mol = 40.985 g.
Step 3: Calculate the total mass of the solution:
The mass of water is given as 300 grams.
Step 4: Calculate the concentration in percentage by mass:
Concentration = (mass of solute / mass of solution) * 100
= (40.985 g / (40.985 g + 300 g)) * 100
= (40.985 g / 340.985 g) * 100
≈ 12.03%
Therefore, the concentration of sodium phosphate in the solution is approximately 12.03% by mass.
To calculate the concentration in percentage by mass, you need to determine the mass of the solute (sodium phosphate) and the mass of the solution (sodium phosphate + water).
1. Find the molar mass of sodium phosphate (Na3PO4):
Na = 22.99 g/mol
P = 30.97 g/mol
O = 16.00 g/mol
Molar mass of Na3PO4 = (3 * Na) + P + (4 * O)
2. Calculate the mass of sodium phosphate:
Mass (in grams) = 0.250 moles * Molar mass (g/mol)
3. Calculate the mass of the solution:
Mass of solution = Mass of water + Mass of sodium phosphate
Since the question states that 0.250 moles of sodium phosphate is dissolved in 300 grams of water, the mass of the solution is 300 grams + Mass of sodium phosphate (from step 2).
4. Calculate the concentration in percentage by mass:
Concentration (%) = (Mass of solute / Mass of solution) * 100
Substitute the values calculated from steps 2 and 3 into the formula to get the concentration in percentage by mass.