In this question, we have a dilution situation, in which we have an initial concentration of the substance, 1.3M and an initial volume 0.40L, but after a while, we have now a volume of 0.80 L and a new concentration, we will be using the Dilution formula:
M1V1 = M2V2
We have:
M1 = 1.3 M
V1 = 0.40 L
M2 = ?
V2 = 0.80 L
Now we will add these values into the formula:
1.3 * 0.40 = 0.80 * M2
0.52 = 0.80M2
M2 = 0.65 M, this will be the new concentration of the substance after adding more water
