Helium gas would be the one to effuse faster as compared to krypton. This is because krypton is heavier than helium. Heavier molecules would require more energy to move so they tend to effuse slower than molecules that are lighter which will only require less energy.
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%
The answer is A. It is an alkyn. There is a triple bond