7.86 is the pOH of water at this temperature of 100 degrees celsius.
Option E is the right answer.
Explanation:
Data given:
Kw = 51.3 x 
pOH = ?
we know that pure water is neutral and will have pH pf 7.
The equation for relation between Kw and H+ and OH- ion is given by:
Kw = [H+] [OH-}
here the concentration of H+ ion and OH- ion is equal
so, [H+]= [OH-]
Putting the values in the equation of Kw
pKw = -log[Kw]
pKw = -log [51.3 x
]
pKw = 12.28
since H+ ion OH ion concentration is equal the pH of water is half i.e. 6.14
Now, pOH is calculated by using the equation:
14 = pOH + pH
14- 6.14 = pOH
pOH = 7.86
I believe it is A because the plant is offering protection while the bacteria is converting it in to nitrogen that the plant can use!
MA= output force/ input force
MA= 100N/20N
MA= 50
6.022 x 10 23 titanium atoms
In 47.88 grams of titanium, there is one mole, or 6.022 x 1023 titanium atoms.
Hope this helps :)