We assume that we have Ka= 4.2x10^-13 (missing in the question)
and when we have this equation:
H2PO4 (-) → H+ + HPO4-
and form the Ka equation we can get [H+]:
Ka= [H+] [HPO4-] / [H2PO4] and we have Ka= 4.2x10^-13 & [H2PO4-] = 0.55m
by substitution:
4.2x10^-13 = (z)(z)/ 0.55
z^2 = 2.31x 10^-13
z= 4.81x10^-7
∴[H+] = 4.81x10^-7
when PH equation is:
PH= -㏒[H+]
= -㏒(4.81x10^-7) = 6.32
X is always the independent variable
Answer:
Aristotle believes that all material substances are matter and form.
Explanation:
If you remember from the four causes, the matter is one cause and form is another cause. Substance theory says that substances are the ultimate things in the universe
1.Calculate the number of mole of O2: 48/32=1.5 mol
2.Calculate the number of mole of H2 by mole ratio: 1.5 x 1/2=0.75 mol
3.Calculate the answer:
0.75 x 2=1.5g
Answer:a) 11.34 g of ethane 
can be formed
b) 
is the limiting reagent
c) 3.44 g of the excess reagent remains after the reaction is complete
Explanation:
To calculate the moles :
1. 
2. 
According to stoichiometry :
1 mole of require 1 mole of 
Thus 0.378 moles of will require=
of
Thus is the limiting reagent as it limits the formation of product and is the excess reagent.
moles of left = (2.10-0.378) = 1.72 moles
mass of left=
According to stoichiometry :
As 1 mole of give = 1 mole of 
Thus 0.378 moles of give = of
Mass of 
Thus 11.34 g of ethane is formed.
