The question is incomplete, complete question is ;
Allura Red (AR) has a concentration of 21.22 ppm. What is this is micro moles per liter? Report the precise concentration of the undiluted stock solution #1 of AR in micromoles per liter. This is your most concentrated (undiluted) standard solution for which you measured the absorbance. Use 3 significant figures. Molarity (micro mol/L) =
Answer:
The molarity of the solution of allura red is 42.75 micro moles per Liter.
Explanation:
The ppm is the amount of solute (in milligrams) present in kilogram of a solvent. It is also known as parts-per million.
To calculate the ppm of oxygen in sea water, we use the equation:
![\text{ppm}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^6](https://tex.z-dn.net/?f=%5Ctext%7Bppm%7D%3D%5Cfrac%7B%5Ctext%7BMass%20of%20solute%7D%7D%7B%5Ctext%7BMass%20of%20solution%7D%7D%5Ctimes%2010%5E6)
Both the masses are in grams.
We are given:
The ppm concentration of allura red = 21.22 ppm
This means that 21.22 mg of allura red was present 1 kg of solution.
Mass of Allura red = 21.22 mg = ![21.22\times 0.001 g](https://tex.z-dn.net/?f=21.22%5Ctimes%200.001%20g)
1 mg = 0.001 g
Mass of solution = 1 kg = 1000 g
Density of the solution = Density of water = d = 1.00 g/mL
( since solution has very small amount of solute)
Volume of the solution :
![=\frac{1000 g}{1.00 g/mL}=1000 mL](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1000%20g%7D%7B1.00%20g%2FmL%7D%3D1000%20mL)
1000 mL = 1 L
Volume of the solution, V = 1 L
Moles of Allura red = ![\frac{21.22\times 0.001 g}{496.42 g/mol}=4.275\times 10^{-5} mol=4.275\times 10^{-5}\times 10^{6} \mu mole](https://tex.z-dn.net/?f=%5Cfrac%7B21.22%5Ctimes%200.001%20g%7D%7B496.42%20g%2Fmol%7D%3D4.275%5Ctimes%2010%5E%7B-5%7D%20mol%3D4.275%5Ctimes%2010%5E%7B-5%7D%5Ctimes%2010%5E%7B6%7D%20%5Cmu%20mole)
Molarity of the solution ;
![=\frac{\text{Moles of solute}}{\text{Volume of solution(L)}}](https://tex.z-dn.net/?f=%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20solute%7D%7D%7B%5Ctext%7BVolume%20of%20solution%28L%29%7D%7D)
![M=\frac{4.275\times 10^{-5}\times 10^6 \mu mol}{1 L}=42.75 \mu mol/L](https://tex.z-dn.net/?f=M%3D%5Cfrac%7B4.275%5Ctimes%2010%5E%7B-5%7D%5Ctimes%2010%5E6%20%5Cmu%20mol%7D%7B1%20L%7D%3D42.75%20%5Cmu%20mol%2FL)
The molarity of the solution of allura red is 42.75 micro moles per Liter.