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
Answer:
a. 342.9 kJ of heat are absorbed.
Explanation:
Calculation of the moles of
as:-
Mass = 20.00 g
Molar mass of
= 17.031 g/mol
The formula for the calculation of moles is shown below:
Thus,

Given that:- 
It means that 1 mole of
undergoes reaction and absorbs 1168\ kJ of heat
So,
1168 mole of
undergoes reaction and absorbs
of heat
<u>Amount of heat absorbed = + 342.9 KJ</u>
Answer:
(before researching)it weighs a positive infinity ∞
Explanation:
(after researching)Our galaxy weighs in at around 10^42 kilograms and the entire visible universe reaches something like 10^53. You can try to convert those figures to something a little more familiar, such as the weight of a blue whale, by subtracting 5 from any of those exponents.
hope this helps have a great day also brainly would be very much appreciated
and here's a meme