Answer:
Explanation:
Since water has a chemical formula of H2O , there will be 2 moles of hydrogen in every mole of water. In one mole of water, there will exist approximately 6.02⋅1023 water molecules.
Matter is never destroyed, nor created. So, this is false.
Oxygen 4. The fatty acid chain of the lipids is often referred to as a hydrocarbon chain.
Here we have to get the correct statements among the given, applicable for Diels-Alder reaction.
The true statements in case Diels-Alder reaction are-
1. An excess of Maleic anhydride is used.
2. The I.R. of the products are indistinguishable.
The Diels-Alder reaction is the most is the most important cyclo-addition reaction in organic chemistry. These are addition reactions in which ring systems are formed without eliminating any compounds.
There remains one diene and one dienophile. The reaction is reversible in nature and requires elevated temperature to obtain its transition state. The reaction rate become faster in certain condition like using of polar solvents.
Among the given statements the following statements are true-
1. An excess of maleic anhydride (the most effective di-enophile) is used to process the reaction in forward direction.
2. The products obtain in this reaction are stereoisomers thus are indistinguishable by infrared spectroscopy (IR).
The statements which are not true for the Diels-Alder reaction:
3. The re-crystallization of the products by any polar solvent like methanol is not feasible as it will cause the retro reaction due to stability of the transition state in polar solvent.
4. Cleaning of glassware are compulsory for any reaction it is not specifically true for Diels-Alder reaction.
5. The reaction occurs at elevated temperature thus flame is required.
Answer:
- Brush off any chemical dust around the balance after each use
- Alert your TA or instructor about any issues with the balance
Explanation:
The best practices while sharing a lab balance with other students includes alerting your TA or instructor about issues with the balance and Brushing off any chemical dust around the balance after each use. the practices will help to avert/reduce the work hazards associated with working with a balance.
Brushing off any chemical dust after each use will reduce the chemical hazards in the lab while Alerting your instructor about any issues with the balance helps to eliminate mechanical hazards that a faulty balance can pose