We can say an atom is electrically neutral if both electron (for electric charge) and proton (for positive charge) have the exact same amount
Since the number are needed in some amount to be considered stable (*2-1st level<span>-need 8 for valence level) , </span><span> The atom that has 7 protons and 7 electrons would be considered enough</span>
Explanation:
The given reaction is as follows.
Hence, number of moles of NaOH are as follows.
n =
= 0.005 mol
After the addition of 25 ml of base, the pH of a solution is 3.62. Hence, moles of NaOH is 25 ml base are as follows.
n =
= 0.0025 mol
According to ICE table,
Initial: 0.005 mol 0.0025 mol 0 0
Change: -0.0025 mol -0.0025 mol +0.0025 mol
Equibm: 0.0025 mol 0 0.0025 mol
Hence, concentrations of HA and NaA are calculated as follows.
[HA] =
[NaA] =
Now, we will calculate the value as follows.
pH =
=
= 3.42
Thus, we can conclude that of the weak acid is 3.42.
1.5 × 10^-6 i would think
The 2 L of sucrose stock solution would contain similar
concentration with the 100 mL aliquot. Therefore the concentration of aliquot
is still 2 M.
The molar mass of sucrose is 342.3 g / mol. Therefore the
mass in a 100 mL (0.1 L) aliquot is:
mass = (2 mol / L) * 0.1 L * (342.3 g / mol)
<span>mass = 68.46 g</span>
Answer is (b)
2,3,1 is the stoichiometry
The values in front of the elements are the stoichiometric values
(Since Al2Br6 has no value in front, it's considered 1)