A water molecule consists of three atoms; an oxygen atom and two hydrogen atoms, which are bond together like little magnets.
An iron pot is made up of only one substance, iron. Iron is an element classified as a transition metal
Iron. Elementsare pure substances that are made up of one kind of atom. Pizza is not an element because it is a mixture of many substances. Water is a pure substance, but it contains two kindsof atom: oxygen and hydrogen.
It is a compound because a compound is two or more different elements chemically combined.
[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 = ![[H_{3}O^{+}]](https://tex.z-dn.net/?f=%20%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%20%20)
=![[FCH_{2}COO^{-}]](https://tex.z-dn.net/?f=%20%5BFCH_%7B2%7DCOO%5E%7B-%7D%5D%20%20)
= 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>
