1.0 of a 4.0 solution is added to water so that the final volume is 8.0 .
Your statement without units is nonsense.
To find the amount of 1.0 of a 4.0 solution that needs to be added to water to obtain a final volume of 8.0, we can use the concept of concentration and the equation:
C1V1 = C2V2
where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.
In this case, the initial concentration is 4.0, the initial volume is unknown (let's call it V), the final concentration is 1.0, and the final volume is 8.0.
Plugging these values into the equation, we have:
4.0 x V = 1.0 x 8.0
Simplifying the equation:
4.0V = 8.0
Dividing both sides by 4.0:
V = 8.0 / 4.0
V = 2.0
Therefore, to obtain a final volume of 8.0, 2.0 of the 4.0 solution needs to be added to the water.