C) Step 1: a horizontal spinning effect is formed from wind shear
Step 2: warm rising air shifts the horizontal rotation to a vertical rotation
Step 3: the vertical rotation expands and extends
First, we need to get the value of Ka:
when Ka = Kw / Kb
we have Kb = 1.8 x 10^-5
and Kw = 3.99 x 10^-16 so, by substitution:
Ka = (3.99 x 10^-16) / (1.8 x 10^-5) = 2.2 x 10^-11
by using the ICE table :
NH4+ + H2O →NH3 + H+
intial 0.013 0 0
change -X +X +X
Equ (0.013-X) X X
when Ka = [NH3][H+] / [NH4+]
by substitution:
2.2 x 10^-11 = X^2 / (0.013 - X) by solving this equation for X
∴X = 5.35 x 10^-7
∴[H+] = X = 5.35 x 10^-7
∴PH = - ㏒[H+]
= -㏒(5.35 x 10^-7)
= 6.27
The given question is incomplete. The complete question is:
In the chemical reaction: , with 8 grams of and 16 grams of and the reaction goes to completion, what is the excess reactant and how much of that would remain?
A) 6 grams of
B) 7 grams of
C) 8 grams of
D) 12 grams of
E) 14 grams of
Answer: A) 6 grams of
Explanation:
To calculate the moles :


According to stoichiometry :
1 moles of
require 2 moles of 
Thus 0.5 moles of
will require=
of 
Thus
is the limiting reagent as it limits the formation of product and
is the excess reagent.
(4.0-1.0) = 3.0 moles of are left unreacted
Mass of remained=
Thus 6.0 g of
will remain.
Ionic bonds involve the transfer of electrons from metal to non metal
covalent bonds involve sharing of electrons between two non metal