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:
glucose and galactose
concentration of the enzyme
temperature and pH
glucose and galactose
Explanation:
Enzymes are biological catalysts. They catalyze various biochemical reactions in the body. Enzymes are proteins.
The enzyme responsible for the breakdown of lactose is lactase. This enzyme catalyzes the breakdown of lactose to glucose and galactose. Galactose is about 65% as sweet as sucrose.
The rate of enzyme reaction is influenced by the concentration of the enzyme. As the concentration of the enzyme is increased, the velocity of the reaction proportionately increases.
Temperature and pH are important environmental factors that affect the rate of enzyme catalyzed reaction because they influence the activity of the enzyme and may even denature the enzyme.
Explanation:
Arsenic is a solid chemical element that is used especially in wood preservatives, alloys, and semiconductors and is extremely toxic in both pure and combined forms.
A poisonous trioxide As2O3 or As4O6 of arsenic is used especially as an insecticide or weed killer.
