One liter of a buffer contains 2.00 Molar NaA and 2.00 Molar HA. (A- is the anion of an acid) 15.00 g NaOH is added. (Assume no volume change) What is the new pH?
HA (aq) + H2O (l) A - (aq) + H3O+ (aq) Ka = 2.3 x 10-11

The new pH is 10.8031

Explanation:

Given information:

[NaA] = concentration = 2 M

[HA] = concentration = 2 M

V = volume = 1 L

15 g of NaOH added

Question: What is the new pH, pH = ?

Moles of NaA:

Moles of HA:

Moles of NaOH:

The reaction:

HA + NaOH → NaA + H₂O

Moles of NaA = 2 + 0.375 = 2.375 moles

Moles of HA = 2 - 0.375 = 1.625 moles

The value of Ka is 2.3x10⁻¹¹

The pKa:

Applying the Henderson's Hasselbach equation

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.