To what volume should you dilute 125mL of an 8.00M CuCl2 solution so that 50.0mL so
that 50.0 mL of the diluted solution contains 5.9 g CuCl2?
moles CuCl2 = 5.9 g / molar mass CuCl2
molarity = moles CuCl2 / .0500 L
diluted volume = (8.00 M / molarity) * 125 mL
8.0 M CuCl2 contains 8 molsCuCl2/L of solution. ALL of the following calculations are rounded so if you need more accurate number you should recalculate everything including the atomic masses and molar masses.
1 mol CuCl2 = 63.5 + 2*35.5 = approximately 134 g; therefore, there are 8.0 x 134 = about 1072 grams CuCl2 in 1 L.
moles CuCl2 in 5.9 g = 5.9/134 = 0.044. That in 50 mL is (0.044/0.050) = 0.88 M.
The dilution formula is mLa x Ma = mLb x Mb.
125 mL x 8.0 M = mLb x 0.88 M
mL b = 125 x 8.0/0.88 = 1,136 mL.; therefore, take 125 mL of the 8.0 M CuCl2 and dilute it to 1,136 mL.
That should do it. Check it.
8.0 M CuCl2 x 125 mL/1,136 mL = 0.88 M or 0.88 mols/L.
0.88 mols/L x 0.050 L = 0.044 moles in the 50 mL.
Then 0.044 x 134 g/mol = 5.897 = essentially 5.9. It will be 5.9 if you clean up the math and the rounding etc. Post your work if you get stuck.
To determine the volume to which you should dilute the 8.00M CuCl2 solution, you can use the equation for dilution:
C1V1 = C2V2
Where C1 and V1 are the initial concentration and volume of the solution, and C2 and V2 are the final concentration and volume of the solution.
Given:
C1 = 8.00M (initial concentration)
V1 = 125mL (initial volume)
C2 = unknown (final concentration)
V2 = 50.0mL (final volume)
The goal is to find the final concentration, C2. However, we are given the mass of CuCl2 (5.9g) in the diluted solution. To calculate the final concentration, we need to convert the mass to moles using the molar mass of CuCl2.
The molar mass of CuCl2 is:
1 atom of Cu = 63.55 g/mol
2 atoms of Cl = 2 * 35.453 g/mol = 70.906 g/mol
Molar mass of CuCl2 = 63.55 + 70.906 = 134.456 g/mol
Now, we can calculate the moles of CuCl2 in the diluted solution:
moles = mass / molar mass
moles = 5.9g / 134.456 g/mol
Next, we can use the equation for concentration to find the final concentration, C2:
C2 = moles / V2
Now, we have all the information needed to calculate the final concentration and volume:
C1V1 = C2V2
(8.00M)(125mL) = C2(50.0mL)
Rearranging the equation to solve for C2:
C2 = (8.00M)(125mL) / (50.0mL)
Now plug in the values to calculate C2:
C2 = (8.00M)(125mL) / (50.0mL)
C2 = 20.0M
Therefore, the final concentration of the diluted solution is 20.0M.