1.59moles
Explanation:
Mass of CaO = 89.23g
Unknown
Number of moles = ?
Solution:
The mole is a unit of measurement in chemistry used to delineate the number of particles an atom contains.
A mole of a substance contains the avogadro's number of particles.
Number of moles = 
Molar mass of CaO = 40 + 16 = 56g/mol
Number of moles = 
= 1.59moles
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The answer is Al.
If it is a main group element with 3 electrons in its Lewis dot structure, it must be in group 3A. If it is in the 3p orbital section, then it must be in period 3, since the p orbital is a valence orbital and the number that preceeds it is the principal quantum number. Therefore, your answer is the element in period 3 and group 3A, which is aluminum.
Answer:
C. spontaneous at all temperatures
Explanation:
The spontaneity of reaction is determined by the sign of the gibbs free energy.
A negative sign denotes that the reaction is spontaneous, positive sign means the reaction is not spontaneous.
From the question;
ΔS° = +253 J/K
ΔH° = -125 kJ/mol
ΔG = ΔH° - TΔS°
From the data given, the condition in which we can obtain a negative value of G, is at any value of T.
For any value of T, G would always be a negative value.
This means the correct option is option C.
A dissolving liquid composed of polar molecules is a polar solvent.
The distinction of polar and non-polar liquids is important because the like dissolves like rule. This rule states that the solubility is greater when the polarity of the liquid is similar to the polarity of the solute.
So, to dissolve polar compounds (e.g. ionic compounds) you should use polar solvents (e.g. water).
Answer: polar solvent
A) heating a pan of water until the water is all gone because then it would change from a liquid top a gas.
