I have done this so many way and can't seen to get the right answer please help!
I'm looking for the Concentration of NiCl2, M from the following
Volume of 0.390 M NiCl2, mL 4.0 3.0 2.0 1.0
Volume of water, mL, 0 1.0 2.0 3.0
Absorbance 0.858 0.644 0.429 0.215
I keep getting 3.432 for the first one and it's not right.
You need to clarify the post. If you have 4.0 mL of 0.390M NiCl2 and you add no H2O to it then (NiCl2) = 0.390M. What are you looking for and what does the absorbance have to do with it? And which are you calling the "first" one?
To calculate the concentration of NiCl2, M, we can use the Beer-Lambert Law, which relates the absorbance of a solution to its concentration.
The formula for the Beer-Lambert Law is:
A = ε * c * l
where:
A is the absorbance,
ε is the molar absorptivity (a constant specific to the substance and wavelength of light used),
c is the concentration of the solution, and
l is the path length (the distance that the light travels through the solution).
In this case, we have four different solutions with different volumes of 0.390 M NiCl2 and varying amounts of water. We also have the corresponding absorbance values for each solution.
To find the concentration of NiCl2 in each solution, we need to rearrange the Beer-Lambert Law formula to solve for c:
c = A / (ε * l)
First, consider the solution with a volume of 4.0 mL of 0.390 M NiCl2. The absorbance is 0.858. To find the concentration, we need to know the path length (l) and molar absorptivity (ε). Do you have information about the path length and molar absorptivity?
To find the concentration of NiCl2, M from the given information, we can use the Beer-Lambert Law, which relates the concentration of a solution to the absorbance of light passing through it. The formula for the Beer-Lambert Law is:
A = εcl
Where A is the absorbance, ε is the molar absorptivity (a constant specific to the substance), c is the concentration, and l is the path length.
In this case, we are given the absorbance values for different volumes of the solution. We can rearrange the Beer-Lambert Law formula to solve for the concentration (c) by dividing both sides of the equation by εl:
c = A / (εl)
Now, let's calculate the concentrations for each volume of the solution using the given data:
For the first volume:
A = 0.858, l = 1.0 cm (assuming a standard path length)
We need to find ε, the molar absorptivity, which is typically given in the problem or can be looked up in a reference.
Once we have ε, we calculate:
c = 0.858 / (ε * 1.0)
Please provide the molar absorptivity value for NiCl2 so we can calculate the concentration accurately.