a solution is prepared by dissolving 4.87 g of sodium dichromate in 25.0 ml of water. (d=1.00g/mL).calculate

a. the mass percent of sodium dichromate in the solution.
b. the mass percent o water in the solution.
c the mole fraction of sodium dichromate in the solution.

How much of this do you know how to do?
Show as much as you can do and I can help from there.

well mass percent is mass solute divided by total mass solution times 100..so would it be..25.0/4.87 x 100?

Your formula is ok. Your use of it is not.
[mass solute/total mass]x100=
4.87 g Na2Cr2O7 is the solute.
Total mass = 4.87 + 25 = ??
You do the math.

b) Solvent is water so mass percent H2O = mass H2O (25 g)/total mass
total mass still 4.87 + 25 = ??
You do the math.

c) mol fraction Na2Cr2O7 =
mols Na2Cr2O7/total mols.

mol Na2Cr2O7 = 4.87/molar mass = ??
mol H2O = 25 g/molar mass H2O = ??

You do the math.
Post your work if you get stuck.

a) To calculate the mass percent of sodium dichromate in the solution, we need to determine the total mass of the solution. The mass of sodium dichromate is given as 4.87 g, and we need to add the mass of water, which is calculated by multiplying the volume (25.0 mL) by the density (1.00 g/mL):

Mass of water = volume x density = 25.0 mL x 1.00 g/mL = 25.0 g

Total mass of solution = mass of sodium dichromate + mass of water = 4.87 g + 25.0 g = 29.87 g

Now we can calculate the mass percent of sodium dichromate:

Mass percent = (mass of sodium dichromate / total mass of solution) x 100%
Mass percent = (4.87 g / 29.87 g) x 100% = 16.28%

b) To calculate the mass percent of water in the solution, we can use the same formula:

Mass percent = (mass of water / total mass of solution) x 100%
Mass percent = (25.0 g / 29.87 g) x 100% = 83.72%

c) To calculate the mole fraction of sodium dichromate in the solution, we need to find the number of moles of sodium dichromate and the number of moles of water.

Number of moles of sodium dichromate = mass of sodium dichromate / molar mass of sodium dichromate
Molar mass of sodium dichromate (Na2Cr2O7) = (2 x atomic mass of Na) + (2 x atomic mass of Cr) + (7 x atomic mass of O)

You can find the atomic masses from the periodic table and perform the calculation to determine the molar mass.

Number of moles of water = mass of water / molar mass of water

Once you have the number of moles for sodium dichromate and water, use the formula:

Mole fraction of sodium dichromate = moles of sodium dichromate / (moles of sodium dichromate + moles of water)

Perform the calculation to find the mole fraction.

Note: If you need help with specific calculations or the molar masses, feel free to provide the values, and I can assist further.