Respuesta :
The question is incomplete, here is the complete question:
What is the concentration, in parts per million, of a solution prepared by dissolving 0.00040 mol HCl in 2.2 L [tex]H_2O[/tex] ? Assume that the volume of the solution does not change when the HCl is added. Assume the density of the solution is the same as that for pure water (1.00 g/mL)
Answer: The concentration of HCl in the solution is 6.64 ppm
Explanation:
- To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
We are given:
Moles of HCl = 0.00040 moles
Molar mass of HCl = 36.5 g/mol
Putting values in above equation, we get:
[tex]0.00040mol=\frac{\text{Mass of HCl}}{36.5g/mol}\\\\\text{Mass of HCl}=(0.00040mol\times 36.5g/mol)=0.0146g[/tex]
- To calculate the mass of water, we use the equation:
[tex]\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}[/tex]
Density of water = 1.00 g/mL
Volume of water = 2.2 L = 2200 mL (Conversion factor: 1 L = 1000 mL)
Putting values in above equation, we get:
[tex]1.00g/mL=\frac{\text{Mass of water}}{2200mL}\\\\\text{Mass of water}=(1.00g/mL\times 2200mL)=2200g[/tex]
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 HCl in the solution, we use the equation:
[tex]\text{ppm}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^6[/tex]
Both the masses are in grams.
We are given:
Mass of HCl = 0.0146 g
Mass of solution = 2200 g
Putting values in above equation, we get:
[tex]\text{ppm of HCl in solution}=\frac{0.0146g}{2200g}\times 10^6\\\\\text{ppm of HCl in solution}=6.64[/tex]
Hence, the concentration of HCl in the solution is 6.64 ppm
