Answer:
a) C6H5COOH + H2O ↔ H3O+ + C6H5COO-
b) [ H3O+ ] = 2.517 E-3 M
c) pH = 2.599
Explanation:
a) balanced equation:
C6H5COOH + H2O ↔ H3O+ + C6H5COO-
⇒ Ka = ( [ H3O+ ] * [ C6H5COO- ] ) / [ C6H5COOH ] = 6.5 E-5
mass balance:
0.10 m = [ C6H5COO- ] + [ C6H5COOH ].....(1)
charge balance:
[ H3O+ ] = [ C6H5COO- ] + [ OH- ] .......[ OH- ] : comes from water, it's not significant
⇒ [ H3O+ ] = [ C6H5COO- ] .........(2)
b) (2) in (1):
⇒ 0.10 M = [ H3O+ ] + [ C6H5COOH ]
⇒ [ C6H5COOH ] = 0.10 - [ H3O+ ]
⇒ Ka = [ H3O+ ]² / ( 0.1 - [ H3O+ ] ) = 6.5 E-5
⇒ [ H3O+ ]² + 6.5 E-5 [ H3O+ ] - 6.5 E-6 = 0
⇒ [ H3O+ ] = 2.517 E-3 M
c) pH = - log [ H3O+ ]
⇒ pH = - Log ( 2.517 E-3 )
⇒ pH = 2.599
The empirical formula is the same as the molecular formula : C₁₀H₅O₂
<h3>Further explanation</h3>
Given
Molecular formula : C₁₀H₅O₂
Required
The empirical formula
Solution
The empirical formula (EF) is the smallest comparison of atoms of compound forming elements.
The molecular formula (MF) is a formula that shows the number of atomic elements that make up a compound.
(empirical formula) n = molecular formula
<em>(EF)n=MF
</em>
(EF)n = C₁₀H₅O₂
If we divide by the number of moles of Oxygen (the smallest) which is 2 then the moles of Hydrogen will be a decimal number (not whole), which is 2.5, then the empirical formula is the same as the molecular formula
What element has the same number of orbits as Hydrogen? Why? Do they have similar properties, why?
Answer:
Helium
Explanation:
Helium has the same number of orbitals as hydrogen because they belong to the same period on the periodic table.
Periods are the horizontal arrangement of elements. Elements in the same period are known to have the same number of electronic shell or orbitals.
In period 1 where we have just Hydrogen and Helium, the number of orbitals is 1.
For properties of a specie, elements in the same group which are the vertical arrangement of elements have the same properties. Since both Hydrogen and helium are in different groups, their properties differ.
