Question

Calculate the molarity of 4.07 x 10^2 mL of solution containing 19.4 g of potassium iodide.

Answer 1

Answer: 0.287 M

Explanation:

Molarity is $M=\frac{n}{v}$. n is moles or solute and v is volume of solution in liters. Since we are given the grams of potassium iodide, we want to convert that into moles. With the volume in mL, we want to convert that to liters.

$19.4 g*\frac{1 mol}{166.0028g} =0.1169 mol$

$4.07*10^2mL*\frac{1L}{1000mL} =0.407 L$

Now that we have moles and liters, we can find molarity.

$M=\frac{0.1169mol}{0.407L} =0.287 M$

Now, we know the molarity is 0.287 M.