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:

20. Would be the right answer
Answer:
H2SO4 + CO3 = H2CO3 + SO4
Explanation:
H2SO4 + CO3
This is the reaction of sulphuric acid and carbon trioxide.
Balanced reaction is;
H2SO4 + CO3 = H2CO3 + SO4
So they react to produce carbonic acid and sulfate.
Answer:
The element is Dysprosium.