Answer:
66.7%
Explanation:
The reaction for the titration of the excess ferrous ion is:
- 5Fe⁺² + MnO₄⁻ + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂O
We calculate the moles of Fe⁺² from the used moles of KMnO₄:
- 0.02 M * 15.0 mL = 0.30 mmol KMnO₄
- 0.3 mmol KMnO₄ *
= 1.5 mmol Fe⁺²
Then we substract those 0.30 mmol from the original amount used:
- 0.1 M * 50.0 mL = 5.0 mmol Fe⁺²
- 5.0 - 1.5 = 3.5 mmol Fe⁺²
The reaction between ferrous ammonium sulfate and MnO₂ is:
- 2Fe⁺² + MnO₂ + 4H⁺ → 2Fe³⁺ + Mn²⁺ + 2H₂O
So we convert those 3.5 mmol Fe⁺² that were used in this reaction to MnO₂ moles:
- 3.5 mmol Fe⁺² *
= 1.75 mmol MnO₂
Then we convert MnO₂ to Mn₃O₄, using the reaction:
- 1.75 mmol MnO₂ *
= 0.583 mmol Mn₃O₄
Finally we convert Mn₃O₄ moles to grams:
- 0.583 mmol Mn₃O₄ * 228.82 mg/mmol = 133.40 mg Mn₃O₄
And calculate the percent
- 133.40 / 200 * 100% = 66.7%
Answer:
c. ₆¹²C and ₆¹³C
Explanation:
Properly writing the given options:
a. ₁¹H and ₁¹H⁺
b. ₇¹⁴N and ₇¹⁴N³⁻
c. ₆¹²C and ₆¹³C
Electrons are the crux of chemical reactions. These negatively charged subatomic particles determines chemical properties of atoms and how they combine with other atoms.
Atoms having the same number of electrons especially in their valence shells shares similar chemical properties.
From the problem above, we have been given some information about the atom.
The mass number is given by the superscript before the symbol of the atom and it signifies the sum of the number of protons and neutrons in the atom.
The atomic number is shown by the subscript and it denotes the number of protons in the atom.
For neutral atoms that has not lost or gained any additional electron, the atomic number is the same as the number of electrons.
The superscript after the atom is the charge on the particle. It represents the number of electrons lost or gained by the atom.
In {c. ₆¹²C and ₆¹³C}, the atom is in a neutral state. Here the atomic number which is 6 is the number of protons in the atom. This is also the number of electrons in the atom. Therefore, the two atoms would have similar chemical properties and behavior.
This is not so for the others as their number electrons are different.
