Parts per million, concentration of ions, and preperations of standard solutions

Question 1

What is parts per million concentration?

Answer 1

Number of units of mass of solute per million units total solution

Question 2

what are the formulas for parts per million

Answer 2

g/g x 10^, g/mL x 10^6
mg/kg, mg/L

Question 3

explain concentration of ions in a solution

Answer 3

When a highly soluble ionic compound dissociates or a strong acid ionizes, the concentration of ions in the solution is proportional to the mole ratio from the balanced chemical equation.

Question 4

What is a standard solution

Answer 4

A solution of an accurately known concentration

Answer 5

1. Calculate the mass of the solid needed to prepare a specific volume of solution at a given concentration.
2. Measure the required mass of solute using an electronic balance.
3. Put the solute into a beaker and dissolve it in about half of the final volume of deionized water.
4. Use a funnel to transfer the solution to a volumetric flask calibrated to measure the desired volume of solution.
5. Rinse the beaker and stirring rod three times with deionized water and transfer rinse water to the flask to ensure all solute has been transferred. Rinse the funnel.
6. Add deionized water to the calibration line, adding dropwise when the solution is close to the line.
7. Invert the flask several times to mix.

Question 6

What is dilution

Answer 6

Dilution is the process of adding water to decrease the concentration of a solution

Question 7

What are the steps to preparing a standard solution by dilution?

Answer 7

1. Use a volumetric pipette to measure the required volume of stock solution.
2. Transfer the volume of stock solution into a volumetric flask calibrated to measure the final volume of the diluted solution.
3. Add deionized water to the calibration line, adding dropwise when the solution is close to the line.
4. Invert the flask several times to mix.