Answer:
Sort the lab chemicals in alphabetical order for quick access.
Become familiar with the chemicals to be used, including exposure or spill hazards.
Locate the spill kits and understand how they are used.
Explanation:
There are many chemicals in a laboratory hence they should be sorted out and arranged in alphabetical order so that theory can easily be identified and located whenever they are required.
The properties of each chemical should be known especially hazards connected to exposure or spill of the chemicals.
The students should also familiarize themselves with the contents of spill kits and how they are used.
Answer:
the first one is branched, the second one is also branched and the third one is cycloalkane
Ok, so the circulatory system in plants and animals is like a method of transport. Both plants and animals use this to transport waste and nutrition.
-Agarvated
(hope this helps, have a great day!)
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%
Isomers have the same molecular formula but they only differ in structure. So, when trans isomer is converted to cis isomer, you would expect a total mass of 25 mg exactly. So, the percent yield would be:
Percent yield = 5 mg/25 mg * 100 = <em>20%</em>
