4. Compound B is provided as a solution and has a specific gravity of 0.65 (Specific gravity is the weight in grams per mL of solution) and is known to be 90% pure (each gram of compound B solution only contains 90% Compound B and 10% of degradation products). 4.5 mL of Compound B is diluted with 55.5mL of water. What is the concentration of this solution?

To find the concentration of the solution, we need to consider the amount of Compound B present in it. Here's how we can calculate it:

1. Calculate the amount of Compound B in 4.5 mL of the original solution:
Since the original solution is 90% pure, we can calculate the amount of Compound B by multiplying 4.5 mL by 0.90:
Amount of Compound B in 4.5 mL = 4.5 mL * 0.90 = 4.05 mL

2. Calculate the specific gravity of Compound B:
Specific gravity is defined as the weight of a substance per unit volume relative to the weight of an equal volume of another substance (usually water). In this case, Compound B has a specific gravity of 0.65, meaning that it weighs 0.65 grams per milliliter (g/mL).

3. Calculate the weight of Compound B in 4.05 mL:
To find the weight of Compound B in grams, we can multiply the volume (in mL) by the specific gravity (in g/mL):
Weight of Compound B in 4.05 mL = 4.05 mL * 0.65 g/mL = 2.6325 grams

4. Calculate the concentration of the solution:
The concentration of the solution is the amount of Compound B (in grams) divided by the total volume of the solution (in milliliters). In this case, the total volume is the sum of 4.5 mL of Compound B and 55.5 mL of water:
Concentration = Weight of Compound B / Total volume of solution
= 2.6325 grams / (4.5 mL + 55.5 mL)
= 2.6325 grams / 60 mL

We can simplify the unit of volume to grams/mL by dividing both numerator and denominator by 10:
Concentration = 0.26325 grams / 6 mL
= 0.043875 g/mL

Therefore, the concentration of the solution is 0.043875 grams per milliliter (g/mL).