# An Exciting Chemistry Problem to Solve!

## How to Calculate the Density of a Solution?

If a student weighs an empty 20 ml volumetric flask and stopper and finds the mass to be 99.895 g. After adding unknown substance to the flask, the same student adds water to the flask to dissolve the unknown substance to a total solution volume of 20.0 ml. The solution and flask are weighed again and the resulting mass is 126.975 g. What is the density of this solution?

## Answer:

The density of the solution is 1.354 g/mL.

To calculate the density of a solution, we need to follow specific steps using the given data. In this problem, we are provided with the mass of the empty flask and the mass of the flask with the solution. Let's break down the calculation process step by step:

## Step 1: Find the Mass of the Solution

To determine the mass of the solution, we subtract the mass of the empty flask from the mass of the flask with the solution:

Mass of the solution = Mass of flask with solution - Mass of empty flask

Mass of the solution = 126.975 g - 99.895 g = 27.080 g

## Step 2: Determine the Volume of the Solution

Since the unknown substance was added to fill the flask to the mark and water was added to dissolve it to a total volume of 20.0 ml, we use 20.0 ml as the volume of the solution.

## Step 3: Calculate the Density of the Solution

Now, we can calculate the density of the solution using the formula:

Density of the solution = Mass of solution / Volume of solution

Plugging in the values we found, we get:

Density of the solution = 27.080 g / 20.0 ml = 1.354 g/mL

Therefore, the density of the solution is 1.354 g/mL. The student successfully solved the problem and found the density of the solution through careful calculations. This shows the importance of understanding the concepts of mass, volume, and density in chemistry. Keep exploring more challenging chemistry problems to enhance your problem-solving skills!