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:
yes 4K + O2 ------>2K20 is true.
The formula of Aldehyde is represented by <span>C2H4O. It has two atoms of Carbon, four atoms of hydrogen and one atom of oxygen. Aldehyde is an organic compound. It's organic because it contains carbon. It has a structure of R-CHO, that consists a carbonyl center bonded to R group and to hydrogen.</span>
Answer: The object will move in the South direction.
Explanation: We are given an object of 400 N and force acting on it is 420 N from the north direction, it means the force is acting towards south.
The object will move in the direction of the net force, which is south direction.
Hence, the correct option is A.