how many milliliters of 0.200 M Na2S2O3 are needed to provide 0.0388 mol Na2S2O3?

M x L = moles.

194 milliliters

To find out how many milliliters of 0.200 M Na2S2O3 are needed to provide 0.0388 mol Na2S2O3, we can use the formula:

Molarity (M) x Volume (L) = Moles

Rearranging the formula, we have:

Volume (L) = Moles / Molarity

Substituting the given values:

Volume (L) = 0.0388 mol / 0.200 M

Volume (L) = 0.194 L

Since 1 L is equal to 1000 mL, we have:

Volume (mL) = 0.194 L x 1000 mL/L

Volume (mL) = 194 mL

Therefore, 194 milliliters of 0.200 M Na2S2O3 are needed to provide 0.0388 mol Na2S2O3.

To solve this problem, we can use the equation:

Molarity (M) = moles (mol) / volume (L)

We are given the molarity (0.200 M) and we need to find the volume in milliliters (mL) needed to provide a certain number of moles (0.0388 mol).

First, we rearrange the equation to solve for volume:
Volume (L) = moles (mol) / molarity (M)

Now, we can plug in the values we have:
Volume (L) = 0.0388 mol / 0.200 M

Next, we need to convert the volume from liters to milliliters. We know that 1 L = 1000 mL.

Volume (mL) = Volume (L) x 1000 mL/L

Calculating the volume:

Volume (L) = 0.0388 mol / 0.200 M
= 0.194 L

Volume (mL) = 0.194 L x 1000 mL/L
= 194 mL

Therefore, 194 milliliters of 0.200 M Na2S2O3 are needed to provide 0.0388 mol Na2S2O3.