Answer:
- <u>First choice: 0.042</u>
Explanation:
Given decomposition reaction:
- 1PCl₅ (g) ⇄ 1PCl₃ + 1Cl₂(g)
Equilibrium constant:
Stoichiometric coefficients and powers equal to 1 are not usually shown as they are understood, but I included them in order to shwow you how they intervene in the equilibrium expressions: each concentration is raised to a power equal to the respective stoichiometric coefficient in the equilibrium equation.
So, your calculations are:

Answer:
Distillation is an important commercial process that is used in the purification of a large variety of materials. However, before we begin a discussion of distillation, it would probably be beneficial to define the terms that describe the process and related properties. ... Elevation of the boiling point with an increase in external pressure, while important in cooking and sterilizing food or utensils, is less important in distillation.
Explanation:
Moles of K = 32.4/39 = 0.83 mole. According to stoichiometry, 2 moles of K produces 1mole of H2. Therefore, 0.83 mole of K produces = 0.83/2 = 0.415 moles of H2. Therefore number molecules of H2 = moles of H2 x 6.02 x 10^23 = 2.4983 x 10^23 molecules. Hope this helps!