Which of the following is not an example of a molecule?
2 answers:
Answer : The option is, (D) Mn
Explanation :
Pure substance : It is defined as a substance that is made by the combination of only one type of atom or only one type of molecule.
Compound : It is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Element : It is a pure substance which is composed of atoms of similar elements.
Molecule : It is the smallest particle in the chemical compound or chemical element that has the same chemical properties of that compound or element.
Option A :
is molecule of element.
Option B :
is molecule of compound.
Option C :
is molecule of compound.
Option D :
is and element.
Hence, the element Mn is not an example of a molecule.
You might be interested in
Answer:
pH = 11.95≈12
Explanation:
Remember the reaction among aqueous acetic acid () and aqueous sodium hydroxide (NaOH)
First step. Need to know how much moles of the substances are present
= 0.0025 mol NaOH
0.003 mol NaOH * / 1 mol NaOH = 0.003 mol CH_3COOH[/tex]
NaOH is in excess. Now, how much?
0.003 mole NaOH - 0.0025 mole NaOH = 0.0005 mole NaOH
Then, that amount in excess would be responsable for the pH.
Third step. Know the pH
Remember that pH= -log[H+]
According to the dissociation of water equilibrium
Kw=[H+]*[OH-]= 10^(-14)
The dissociation of NaOH is
NaOH ->
Now, concentration of OH^{-}[/tex] would be given for the excess of NaOH.
[OH-]= 0.0005 mole / 0.055 L = 0.00909 M
Careful: we have to use the total volumen
Les us to calculate pH