Density Questions?

Question

A solution containing 45.03g of liquid A and 17.55g of liquid B has a density of 1.904g/mL. On adding further 19.40g of liquid B to the mixture, the density drops to 0.972g/mL. Assuming that the volumes are additive, calculate the density of liquid B in g/mL.

Answer 1

Here's how you do it: Let v1, m1 and d1 be initial volume, mass and density, and let suffix "2" be for added liquid and "3" for final mixture.
Given m1, d1, m2 and d3, find d2.
Get v1 from m1 and d1.
Get m3 from m1 and m2.
Get v3 from m3 and d3.
Get v2 from v1 and v3.
Get d2 from m2 and v2.
You should get about 0.377 g/ml.