Question

What is the concentration of Iodine I2 molecules in a solution containing 2.54 g of iodine 250 cm3 of solution? A 0.01mol/dm3 B 0.02mol/dm3 C 0.04mol/dm3 D 0.08mol/dm3

Answer 1

Answer:

C. 0.04 moles per cubic decimeter.

Explanation:

The molar mass of the Iodine is 253.809 grams per mole and a cubic decimeter equals 1000 cubic centimeters. The concentration of Iodine ($c$), measured in moles per cubic decimeter, can be determined by the following formula:

$c = \frac{m}{M\cdot V}$ (1)

Where:

$m$ - Mass of iodine, measured in grams.

$M$ - Molar mass of iodine, measured in grams per mol.

$V$ - Volume of solution, measured in cubic decimeters.

If we know that $m = 2.54\,g$, $M = 253.809\,\frac{g}{mol}$ and $V = 0.25\,dm^{3}$, then the concentration of iodine in a solution is:

$c = \frac{2.54\,g}{\left(253.809\,\frac{g}{mol} \right)\cdot (0.25\,dm^{3})}$

$c = 0.04\,\frac{mol}{dm^{3}}$

Hence, the correct answer is C.