<span>The reason it will be 7 for some titrations is that when you titrates a strong acid with a strong base for example HCl and NaOH the salt formed is conjugate base of strong acid and will be a very weak base
That means that it cannot produce any OH^-1 and all the H+ has been converted to water.The only source of H+ or OH is water with a Ka of 10^-14 so the pH = -log [H+]=-log 10^-7 = 7
second reason is
When you titrates a weak acid with strong base at equivalence point
only a water solution of the conjugate base exists
CH3COOH + NaOH ----- Na+ CH3COO^-1 + H2O
Since the conjugate base is the conjugate base of a weak acid it will hydrolyze in water like so
for instance Na+ CH3COO^-1 + HCl---- CH3COOH + NaCl the equivalence point will be way BELOW 7 and in the case of above will be less than 5. So pH of 7 at equivalence point is only reached in strong acid strong base titrations.
hope this helps</span>
The speed of light is 299,792,458 meters per second in vacuum.
It's somewhat slower in any material substance, and different in
each substance.
(That's 186,282.4 miles per second.)
Answer:
0.071 moles of Na₃PO₄ .
Explanation:
Given data:
Number of molecules of Na₃PO₄ = 4.3× 10²² molecules
Number of moles = ?
Solution:
1 mole contain 6.022 × 10²³ molecules
4.3× 10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.71× 10⁻¹ mol
0.071 mol
The number 6.022 × 10²³ is called Avogadro number.
"It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance"
Answer:
Iron and aluminum are examples of metals, along with copper, iron, (etc.)
<span>Tf is the freezing point of the solution(the solvent plus solute).
T*f is the freezing point of the pure solvent(without solute)
i is the van't Hoff factor.It is approximately the number of particles in solution that are made for each particle of the solute that is placed into solution.Therefore, for nonelectrolytes, i = 1.
Kf is the freezing point depression constant.For water, Kf = 1.86 Degree C/m, or 1.86 Degree C.kg/mol.
Tf is -1.58 Degree C</span>
