Answer:
A. 32.06 g/mol
Explanation:
The molar mass units are always g/mol
[H_{3}O^{+}] = 0.00770 M
The equilibrium equation representing the dissociation of 

Given [H_{3}O^{+}] = 0.00770 M
Let the initial concentration of acid be x and change y
So y =
=
= 0.00770 M



0.00257 x - 0.00001979 = 0.00005929
x = 0.031 M
Therefore, initial concentration of the weak acid is <u>0.031 M</u>
A. the density stays the same unless given an external catalyst
The formula for phosphorus is P4