Question

Химики отзовитесь!!! Помогите пожалуйста!!! В двух склянках находятся органические вещества( толуол и винилбензол). Докажите, какое вещество находится в каждой склянке, для чего-напишите уравнения качественных реакций,укажите их признаки-укажите условия реакций-назовите продукты реакций

Answer 1

Толуол не обесцвечивает бромную воду, а стирол (винилбензол)  обесцвечивает

C6H5-CH=CH2 +Br2 -> C6H5-CHBr-CH2Br

Answer 2

Identifying the Substances in the Flasks

To determine which substance is present in each flask (toluene and vinylbenzene), we can perform a series of qualitative reactions. These reactions will help us identify the characteristic properties of each substance and distinguish between them.

Qualitative Reactions for Toluene

Toluene is an aromatic hydrocarbon with the chemical formula C7H8. It is commonly used as a solvent and has a distinct odor. Here are some qualitative reactions that can be used to identify toluene:

1. Bromine Water Test: Toluene does not react with bromine water under normal conditions. When bromine water is added to toluene, it remains unchanged, indicating a negative reaction.

Equation: C7H8 + Br2 → No reaction

2. Reaction with Potassium Permanganate: Toluene does not react with potassium permanganate (KMnO4) under normal conditions. When toluene is added to KMnO4, it remains unchanged, indicating a negative reaction.

Equation: C7H8 + KMnO4 → No reaction

3. Reaction with Nitric Acid: Toluene reacts with concentrated nitric acid (HNO3) in the presence of sulfuric acid (H2SO4) to form a mixture of nitrotoluene isomers.

Equation: C7H8 + HNO3 → Mixture of nitrotoluenes

Qualitative Reactions for Vinylbenzene

Vinylbenzene, also known as styrene, is an aromatic hydrocarbon with the chemical formula C8H8. It is used in the production of various plastics and synthetic materials. Here are some qualitative reactions that can be used to identify vinylbenzene:

1. Reaction with Bromine Water: Vinylbenzene readily reacts with bromine water, decolorizing it. This reaction is a characteristic test for the presence of vinylbenzene.

Equation: C8H8 + Br2 → C8H7Br + HBr

2. Reaction with Potassium Permanganate: Vinylbenzene reacts with potassium permanganate (KMnO4) under acidic conditions to form benzaldehyde.

Equation: C8H8 + KMnO4 + H2SO4 → C6H5CHO + MnSO4 + H2O

3. Reaction with Nitric Acid: Vinylbenzene reacts with concentrated nitric acid (HNO3) in the presence of sulfuric acid (H2SO4) to form a mixture of nitrostyrene isomers.

Equation: C8H8 + HNO3 → Mixture of nitrostyrenes

Conclusion

Based on the qualitative reactions described above, we can determine the substances present in each flask:

- The flask containing toluene will show no reaction with bromine water or potassium permanganate. It will react with concentrated nitric acid to form a mixture of nitrotoluene isomers. - The flask containing vinylbenzene will decolorize bromine water, react with potassium permanganate to form benzaldehyde, and react with concentrated nitric acid to form a mixture of nitrostyrene isomers.

Please note that the reactions mentioned above are qualitative tests and may not provide a definitive identification. Additional confirmatory tests or analytical techniques may be required for a more accurate determination of the substances present in the flasks.