Question

1- A sport drink contains 50 Mg of sodium ions and 55 mg of potassium ions per 400 mL serving calculate the concentration of the sodium and potassium ions in ppm.

2- which of piece of lab equipment is used for measuring a precise volume of the final solution?

Erlenmeyer flask , beaker , volumetric flask , test tube , graduated cylinder.

Answer 1

1. ppm is the measurement of concentration used for very Dilute Solutions.

It can be calculated as (ppm) = Mass of solute (mg) / Volume of solution (Litres)

As we know ppm is Parts per Million and it is calculated in milligrams per Litre (mg/L) or Micrograms per millilitre.

Concentration of Sodium ions : mass of sodium ions(given) = 50 mg

Volume of drink(given) = 400mL

converting into Litres = 400 mL x 1 L /1000 mL

= 0.4 L

ppm of Sodium ions = 50 mg / 0.4 L

= 125 mg / L or 125 ppm

Concentration of Potassium ions : mass of Potassium ions(given) = 55 mg

Volume of drink(given) = 400mL

Converting into Litres = 400 mL x 1L /1000 mL

= 0.4 L

ppm of Potassium ions = 55 mg / 0.4 L

= 137.5 mg /L or 137.5ppm

2. Volumetric flask, Burette and glass pipette are used to measure the precise volume of final solution, as they give accurate results.

But in the Question given, options which are matching is only Volumetric flask, as it has high accuracy compared to all other glasswares given.