Answer:
9
Explanation:
n-factor of NaOH = 1
OH⁻ concentration = Normality of NaOH
= Molarity x n-factor
= 10⁻⁵ x 1
= 10⁻⁵
Now, pOH = -㏒(OH⁻)
pOH = -㏒(10⁻⁵)
pOH = 5
We know pH + pOH = 14
pH = 14 - 5 = 9
∴pH of 10⁻⁵M NaOH is 9
Answer: avogadros number/constant
Explanation:
The gram formula mass of P2O5 is 31*2 + 16*5 =142. The mole number of P2O5 is 0.380/142=0.00268 mol. There is 7 atom in one P2O5 molecule. And there is 6.02 * 10^23 molecule per mol. So the answer is 1.13*10^22 atoms.
Argon-40 because it is the isotope with the closest mass to the atomic mass of the element. Making it more stable than the others allowing it to be the most abundant in nature.