What volume (mL) of a concentrated solution of sodium hydroxide (2.00 M) must be diluted to 600.0 mL to make a 0.860 M solution of sodium hydroxide? Express your answer to the nearest tenth mL.

dilution problems can be solved with this.

M x mL = M x mL.

To find the volume of the concentrated solution that needs to be diluted, we can use the equation for dilution:

C₁V₁ = C₂V₂

Where:
C₁ = Concentration of the concentrated solution
V₁ = Volume of the concentrated solution
C₂ = Target concentration
V₂ = Final volume

In this case, we know the following:
C₁ = 2.00 M (concentration of the concentrated solution)
C₂ = 0.860 M (target concentration)
V₂ = 600.0 mL (final volume)

We need to find V₁ (volume of the concentrated solution).

Rearranging the equation, we get:

V₁ = (C₂ * V₂) / C₁

Plugging in the values, we have:

V₁ = (0.860 M * 600.0 mL) / 2.00 M

Calculating this gives us:

V₁ = (516.0 mL) / 2.00

V₁ = 258.0 mL

Therefore, to make a 0.860 M solution of sodium hydroxide, you need to dilute 258.0 mL of the concentrated solution to a final volume of 600.0 mL.