The % yield of Ca(OH)₂ : 62.98%
<h3>Further eplanation
</h3>
Percent yield is the compare of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Reaction
CaO + H₂O ⇒ Ca(OH)₂
mass CaO= 4.2 g
mol CaO(MW=56,0774 g/mol) :

mol Ca(OH)₂ based on mol CaO
mol ratio CaO : Ca(OH)₂,= 1 : 1, so mol Ca(OH)₂ = 0.075
mass Ca(OH)₂(MW=74,093 g/mol) ⇒ theoretical

% yield :

Answer:
A. Both describe ways a solid can change.
Answer: So you could for example say, “IF I through my clothes into the closet. THEN the floor will be visible” I capatlized if and then because you need them in a hypothesis.
Explanation:
So, I don't know the answer for b but I think I found the answer for a.
I sincerely hope this isn't wrong
Since the volume decreased, it means that the pressure is going to rise. Thus, the equilibrium of the reaction will shift in the direction that has the least amount of moles.