Answer:
number of valence electrons
Explanation:
All of the elements in group 17, also known as group 7A, have 7 valence electrons.
No two elements have the same atomic number nor atomic mass in elemental form.
Halogens may have any number of isotopes.
Answer:
[ S2- ] = 4.0 E-47 M
Explanation:
- PbS(s) → Pb2+ + S2-
- HgS(s) → Hg2+ + S2-
∴ Ksp PbS = 3.4 E-28 = [Pb2+]*[S2-]
∴ [Pb2+] = 0.181 M
∴ Ksp HgS = 4.0 E-53 = [Hg2+]*[S2-]
∴ [Hg2+] = 0.174 M
∴ Ksp PbS > Ksp HgS ⇒ precipitate first Hg2+:
∴ [ Hg2+ ] = 1.0 E-6 M
⇒ [S2-] = 4.0 E-53 / 1.0 E-6 = 4.0 E-47 M
Answer:
ethylpentanoate
Explanation:
Alkanoic acids react with alkanols in the presence of mineral acids to yield an ester and water. This is the organic analogue of the inorganic neutralization reaction. The reaction his commonly called esterification. It is an acid catalysed reaction.
The reaction of pentanoic acid and ethanol in the presence of a string acid is shown below;
CH3CH2CH2CH2COOH(aq) + CH3CH2OH(aq) ----> CH3CH2CH2CH2COOCH2CH3(aq) + H2O(l)
The name of the compound formed is ethylpentanoate.
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