What is the percentage strength of a solution made by adding 200ml of purified water to 600ml of a 25% solution?

To find the percentage strength of the final solution after adding 200 ml of purified water to 600 ml of a 25% solution, we start by calculating the total amount of solute in the original solution.

A 25% solution means that there are 25 grams of solute for every 100 ml of solution. In this case, for 600 ml of the 25% solution, the total grams of solute can be calculated as follows:

[

\text{Grams of solute} = \frac{25 \text{ grams}}{100 \text{ ml}} \times 600 \text{ ml} = 150 \text{ grams}

]

Next, we consider the total volume of the new solution after adding 200 ml of purified water:

[

\text{Total volume} = 600 \text{ ml} + 200 \text{ ml} = 800 \text{ ml}

]

Now, we can calculate the percentage strength of the final solution. The percentage strength is determined by the formula:

[

\text{Percentage Strength} = \left( \frac{\text{grams of solute}}{\text{total volume in ml}} \right) \