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:
It takes 1.9
years to distribute all the grains.
Explanation:
In one second,
grains of wheat are distributed.
We are supposed to find the time it would take to Distribute Avogadro number of grains.
1 avogadro number = 6.022 
Number of grains distributed in 1 day = 86400
= 8.64 
Number of grains distributed in 1 year= 8.64 
= 3.1536 
Time taken = 
= 
= 1.9 
Solute - the substance that dissolves into the solvent to produce a homogenous mixture
Solvent - the substance in which a solute dissolves to produce a homogeneous mixture
Carbon oxides (monoxide, dioxide) are gases :)
Molar mass H₃PO₄ = 98.0 g/mol
1 mole ----- 98.0 g
? mole ------ 30.0 g
moles = 30.0 * 1 / 98.0
= 0.306 moles
hope this helps!