Answer:
See explanation
Explanation:
The valence electrons are electrons found on the valence (outermost) shell of an atom.
When an atoms form compounds, there is an exchange of valence electrons between the atoms of one element and the atoms of another element.
Let us consider a typical example, sodium has one valence electron and chlorine has seven valence electrons. This means that chlorine needs one electron to complete its octet while sodium needs to release one electron in order to attain the octet structure.
So, sodium gives out its one electron and becomes a stable sodium ion and chlorine accepts that electron and becomes a stable chloride ion. This is how the compound sodium chloride is formed.
- The mass percent of
Pentane in solution is 16.49%
- The mass percent of
Hexane in solution is 83.51%
<u>Explanation</u>:
- Take 1 kg basis for the vapor: 35.5 mass% pentane = 355 g pentane with 645 g hexane.
-
Convert these values to mol% using their molecular weights:
Pentane: Mp = 72.15 g/mol -> 355g/72.15 g/mol = 4.92mol
Hexane: Mh = 86.18 g/mol -> 645g/86.18 g/mol = 7.48mol
Pentane mol%: yp = 4.92/(4.92+7.48) = 39.68%
Hexane mol%: yh = 100 - 39.68 = 60.32%
Pp-vap = 425 torr = 0.555atm
Ph-vap = 151 torr = 0.199atm
-
From Raoult's law we know:
Pp = xp Pp - vap = yp Pt (1)
Ph = xh Ph - vap = yh Pt (2)
-
Since it is a binary mixture we can write xh = (1 - xp) and yh = (1 - yp), therefore (2) becomes:
(1 - xp) Ph - vap = (1 - yp) Pt (3)
-
Substituting (1) into (3) we get:
(1-xp) Ph - vap = (1 - yp) xp Pp - vap / yp (4)
xp = Ph - vap / (Pp - vap/yp - Pp - vap + Ph - vap) (5)
-
Subbing in the values we find:
Pentane mol% in solution: xp = 19.08%
Hexane mol% in solution: xh = 80.92%
-
Now for converting these mol% to mass%, take 1 mol basis for the solution and multiplying it by molar mass:
mp = 0.1908 mol 72.15 g/mol
= 13.766 g
mh = 0.8092 mol 86.18 g/mol
= 69.737 g
-
Mass% of Pentane solution = 13.766/(13.766+69.737)
= 16.49%
-
Mass% of Hexane solution = 83.51%
Did the someone else have answers? If not then ask again in hopes of someone checking yours out :)
Answer:
23.2 mols
Explanation:
(23.2 mol H2)(2 mol H2O) /(2 mol H2) = 23.2 mol H2O
you have to do stoichiometry - so start of with what you are given, which is 23.2 mols of hydrogen, then to cancel out mols of hydrogen, divide by what is in the equation: so 23.2 mols H2 / 2 mols H2. Next, to get mols of H2O multiply that number by the mols of water in the equation.
this answer makes sense because as you can see in the equation, there are 2 H2:2 H2O, so the amounts should be the same.
hope this helps! make sure to practice because it is ESSENTIAL that you understand this, especially if you plan on taking ap chem. good luck! :)
2MgO
This is called redox reaction. Oxygen is the oxidizing agent to receive 2 electrons from Mg.
Mg is the reducing agent to give 2 electrons to O.
Mg becomes Mg2+ and O becomes O2-. These 2 ions form an ionic structure called MgO