Question

56) If a 360 mL sample of helium contains 0.25 mol of the gas, how many molecules of chlorine gas would occupy the same volume at the same temperature and pressure? a) 1.2 x 1024 b) 6.02 x 1023 c) 3.01 x 1023 d) 1.51 x 1023 e) 7.55 x 1022

Answer 1

Using Avogadro's law, 0.25 mol of chlorine gas (Cl₂) will contain 0.25 x (6.022 x 10²³) = 1.51 x 10²³ molecules, which is option d) in the choices provided.

Step-by-step explanation:

If a 360 mL sample of helium contains 0.25 mol of the gas, the question asks how many molecules of chlorine gas would occupy the same volume at the same temperature and pressure.

Using Avogadro's law, we know that one mole of any gas at the same temperature and pressure occupies the same volume. Helium and chlorine gases would adhere to this principle assuming ideal behavior.

Since 0.25 mol of helium occupies 360 mL, 0.25 mol of chlorine gas (Cl₂) will also occupy 360 mL under the same conditions. One mole of any gas contains Avogadro's number of molecules, which is 6.022 x 10²³. Therefore, 0.25 mol of chlorine gas will contain 0.25 x (6.022 x 10²³) chlorine molecules.

0.25 x (6.022 x 10²³) = 1.5055 x 10²³ molecules, which can be rounded to 1.51 x 10²³, corresponding to option d) in the original question.