- 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
 Pp - vap = yp  Pt                                       (1)
 Pt                                       (1)
Ph = xh  Ph - vap = yh
 Ph - vap = yh  Pt                                       (2)
 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)
 Ph - vap = (1 - yp)  Pt                                   (3)
 Pt                                   (3)
- 
Substituting (1) into (3) we get:
(1-xp)  Ph - vap = (1 - yp)
 Ph - vap = (1 - yp)  xp
 xp  Pp - vap / yp            (4)
 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
 72.15 g/mol 
      = 13.766 g
mh = 0.8092 mol  86.18 g/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%
 
        
             
        
        
        
Answer:
C.5
Explanation:
A number of electrons present in valence shell of penultimate Shell represents the group of elements. 
For s block elements: no.of group=number of valence shell electron.
p block elements: no. of group= 2 + 10 + number of valence electrons.
d block elements: no. of group= number(n-1)d electrons + number of electrons in nth shell.
Here, the differential electron is in p orbital hence, it belongs to p block
No. of group= 2+ 10 + 3=15 i.e 15th group or VA group.
 
        
                    
             
        
        
        
Gibbous refers to the moon when it is more than half full but not completely full. This results in half a circle with a smaller arc on the opposite side. This makes a weird shaped “hump” on that side which is what the humpback means.
        
             
        
        
        
Answer:
A. What is the concentration of nitric acid?
Explanation:
its right