Question

Алкен массой 2,24г может обесцветить 200г бромной воды, массовая доля брома в которой равна 3,2%. Установаите молекулярную формулу алкена

Answer 1

Находим массу брома в бромной воде:
m(Br2) = 200 г * 0,032 = 6,4 г.
Находим количество брома:
v(Br2) = 6,4 г : 160 г/моль = 0,04 моль.
Алкены имеют общую формулу CnH2n, где n >= 2.
Составим уравнение реакции:
СnH2n + Br2 = CnH2nBr2
По уравнению реакции, количество алкена равно количеству брома, значит v(CnH2n) = 0,04 моль.
Находим молярную массу алкена:
М(CnH2n) = 2,24 г : 0,04 г/моль = 56 г/моль = 14n => n = 4, т.е. исходный алкен - С4Н8.

Answer 2

Calculation of the moles of bromine in 200g of bromine water

To determine the molecular formula of the alkene, we first need to calculate the moles of bromine in 200g of bromine water. We can use the mass and the mass fraction of bromine to calculate this.

The mass of bromine in 200g of bromine water can be calculated using the mass fraction of bromine:

Mass of bromine = Mass of bromine water x Mass fraction of bromine

Given that the mass of bromine water is 200g and the mass fraction of bromine is 3.2%, we can calculate the mass of bromine as follows:

Mass of bromine = 200g x 3.2%

Let's calculate the mass of bromine:

Mass of bromine = 200g x 0.032 = 6.4g

Calculation of the moles of the alkene

Next, we need to calculate the moles of the alkene. We are given that the mass of the alkene is 2.24g.

To calculate the moles of the alkene, we can use the molar mass of the alkene. However, since we don't have the molar mass of the alkene, we cannot determine the molecular formula directly.

Unfortunately, the search results provided do not contain the necessary information to determine the molecular formula of the alkene. Therefore, without additional information, it is not possible to determine the molecular formula of the alkene.

If you have any additional information or if there is anything else I can help you with, please let me know!