Question

A student mixes 0.50 L of 0.0020 M Ba(NO3)2 solution with 0.50 L of 0.0080 M Na2SO4 solution. Which equation shows the proper set-up to calculate molar concentration of Ba2+ ions in the new solution?

(0.0020 M)(1 L) = (? M)
(0.0020 M)(0.5 L) = (? M)(1 L)
(0.0020 M)(0.5 L) = (0.0080 M)(1 L)
(0.0020 M)(0.5 L) = (0.0080 M)(0.5)(? L)

Answer 1

Answer:

(0.0020 M)×(0.5 L) = (? M)×(1 L)

Explanation:

To find the concentration of the final solution when you concentrate or dilute a particular solution is done by using the following formula:

initial concentration × initial volume = final concentration × final volume

The question is asking about the concentration of barium ions in the final solution.

initial concentration of Ba²⁺ = 0.0020 M

initial volume = 0.50 L

final concentration = unknown (?)

final volume = volume of the initial solution + volume of the second solution

final volume =  0.50 + 0.50 = 1 L

You insert the values in the equation and you find the answer asked by the question.