Answer:
a) pH = 4.213
b) % dis = 2 %
Explanation:
Ch3COONa → CH3COO- + Na+
CH3COOH ↔ CH3COO- + H3O+
∴ Ka = 1.8 E-5 = ([ CH3COO- ] * [ H3O+ ]) / [ CH3COOH ]
mass balance:
⇒ <em>C</em> CH3COOH + <em>C</em> CH3COONa = [ CH3COOH ] + [ CH3COO- ]
<em>∴ C </em>CH3COOH = 3.40 mM = 3.4 mmol/mL * ( mol/1000mmol)*(1000mL/L)
∴ <em>C</em> CH3COONa = 1.00 M = 1.00 mol/L = 1.00 mmol/mL
⇒ [ CH3COOH ] = 4.4 - [ CH3COO- ]
charge balance:
⇒ [ H3O+ ] + [ Na+ ] = [ CH3COO- ] + [ OH- ]....is negligible [ OH-], comes from water
⇒ [ CH3COO- ] = [ H3O+ ] + 1.00
⇒ Ka = (( [ H3O+ ] + 1 )* [ H3O+ ]) / ( 3.4 - [ H3O+])) = 1.8 E-5
⇒ [ H3O+ ]² + [ H3O+ ] = 6.12 E-5 - 1.8 E-5 [ H3O+ ]
⇒ [ H3O+ ]² + [ H3O+ ] - 6.12 E-5 = 0
⇒ [ H3O+ ] = 6.12 E-5 M
⇒ pH = - Log [ H3O+ ] = 4.213
b) (% dis)* mol acid = <em>C</em> CH3COOH = 3.4
∴ mol CH3COOH = 500*3.4 = 1700 mmol = 1.7 mol
⇒ % dis = 3.4 / 1.7 = 2 %
To count the number of valence electrons we look at the electronic configuration and add the electrons form the electronic shell with the highest principal quantum number.
Rb: [Kr] 5s¹ - 1 valence electron
Xe: [Kr] 5s² 4d¹⁰ 5p⁶ - 8 valence electrons
Sb: [Kr] 5s² 4d¹⁰ 5p³ - 5 valence electrons
I: [Kr] 5s² 4d¹⁰ 5p⁵ - 7 valence electrons
In: [Kr] 5s² 4d¹⁰ 5p¹ - 3 valence electrons
Rank from most to fewest valence electrons:
Xe > I > Sb > In > Rb
Protons: <span>The mass of the proton is about 1,840 times the mass of the electron and slightly less than the mass of the neutron.
Electrons: </span><span>Electrons are arranged around the nucleus of atoms in regions called electron clouds or electron orbits.
Neutrons: </span><span>A neutron is one of two particles found inside the nucleus (central part) of an atom. The other particle is called a proton. Electrons are particles that move around an atom outside the nucleus.</span>
Answer:
The electron cloud
Explanation:
<em>Rutherford’s gold foil experiment</em> showed that the atom consisted of a tiny nucleus inside of a much larger electron cloud.
The diameter of the electron cloud is about 50 000 times that of the nucleus.
