You need to prepare 350ml of 6% solutions using 7% and 2% solutions . How many ml of 2% stock solutions do you need for this order

1 answer

Let's assume you need x ml of 2% stock solution for the order.

The 7% stock solution is not needed for this order.
So, the total volume of the final solution will be x ml.

The concentration of the final solution is given as 6%. This means that the amount of solute in the final solution is 6% of its volume (which is x ml).
Thus, the amount of solute in the final solution will be 6/100 * x ml = 0.06x ml.

Since the 2% stock solution has a concentration of 2%, the amount of solute in the 2% stock solution will be 2/100 * x ml = 0.02x ml.

To prepare the desired concentration, we need to mix the 2% stock solution (0.02x ml) with a certain amount of pure water (0 ml) to make a total of x ml.

The amount of solute in the final solution will be 0.06x ml. Since this amount needs to come from the 2% stock solution, we can equate the two values:

0.06x ml = 0.02x ml

Simplifying this equation by dividing both sides by 0.02:

3x = x

Subtracting x from both sides:

2x = 0

Dividing both sides by 2:

x = 0

The equation shows that the amount of 2% stock solution needed for this order is 0 ml.