Question

Calculate the molar it’s of a solution by adding 250.0 mL of water to 95.00 mL of a 0.157 M solution

Answer 1

0.0432 M

Step-by-step explanation:

To find the new molarity, you need to (1) calculate the number of moles (using the molarity ratio), then (2) calculate the new volume, and then (3) calculate the new molarity. The moles in the first molarity is the same amount in the new molarity. The final answer should have 3 sig figs like the given number with the smallest amount of moles.

(Step 1)

95.00 mL / 1,000 = 0.095 L

Moles:

Molarity = moles / volume

0.157 M = ? moles / 0.095 L

0.0149 = ? moles

(Step 2)

250.0 mL / 1,000 = 0.25 L

New Volume:

0.25 L + 0.095 L = 0.345 L

New Molarity:

Molarity = moles / volume

Molarity = 0.0149 moles / 0.345 L

Molarity = 0.0432 M