Question

The concentration of 150.0 mL of Na2CO3 is found to be 30.0 ppm. What mass of Na2CO3 is dissolved in the solution if the density of the solution is 0.750 g/mL?

Answer 1

First use the definition of ppm unit of concentration

ppm = [grams of solute / grams of solution] * 1,000,000

From that:

 grams of solute = ppm * grams of solution / 1,000,000

Now, you need to find the grams of solution, for which you use the density of the solution and its volume:

density = mass / volume => mass = density * volume

=> mass of solution = 150.0 ml * 0.750 g/ ml = 112.5 g

And, finally, you can calculate the mass of solute

grams of solute = 30 * 112.5 g / 1,000,000 = 0.003375g

Answer: 0.003375 g

Answer 2

Answer:

c

Explanation:

3.38x10^-3G