Question

История открытия элемента брома полна интересных событий. В 1826 году знаменитый немецкий химик Юстус Либих получил красно-бурую жидкость, но принял её за хлорид известного в то время элемента. Дальнейшее изучение этой жидкости Ю. Либих не предпринял, а через месяц узнал об открытии нового простого вещества - брома французским химиком А. Баларом. За какое вещество Ю. Либих принял бром, если известно, что оно содержит 21,85% хлора по массе? В ответе укажите формулу вещества и валентности элементов, образующих вещество. Валентность запишите арабской цифрой. Формула вещества ? Валентность хлора ? Валентность неизвестного элемента ?

Answer 1

Ответ:

Формула вещества  

NaBr

Валентность хлора  

1

Валентность неизвестного элемента  

-1

Объяснение:

Answer 2

Ответ:

FeCl3

1

3

Объяснение:

Answer 3

History of the Discovery of Bromine

The history of the discovery of the element bromine is indeed filled with interesting events. In 1826, the renowned German chemist Justus von Liebig obtained a reddish-brown liquid, which he mistakenly identified as a chloride of a known element at that time. However, he did not further investigate this liquid and, a month later, he learned about the discovery of a new simple substance called bromine by the French chemist Antoine Balard.

According to the information provided, the substance that Justus von Liebig mistook for bromine contains 21.85% chlorine by mass. To determine the formula and valencies of the elements in this substance, we can use the concept of percent composition and assume that the sample contains 100 grams of the substance.

Let's calculate the mass of chlorine in the sample: - Mass of chlorine = 21.85 grams (given)

Since the sample contains 100 grams of the substance, we can calculate the mass of the other element: - Mass of the other element = 100 grams - 21.85 grams = 78.15 grams

Now, let's calculate the moles of chlorine and the moles of the other element: - Moles of chlorine = mass of chlorine / molar mass of chlorine - Moles of the other element = mass of the other element / molar mass of the other element

Using the periodic table, we can find the molar masses of chlorine and the other element: - Molar mass of chlorine (Cl) = 35.45 g/mol - Molar mass of the other element = unknown

To find the molar mass of the other element, we can use the fact that the sample contains 100 grams of the substance. Therefore, the moles of chlorine and the moles of the other element should add up to 100 grams.

Let's calculate the moles of chlorine and the moles of the other element: - Moles of chlorine = 21.85 grams / 35.45 g/mol - Moles of the other element = 78.15 grams / molar mass of the other element

Since the moles of chlorine and the moles of the other element should add up to 100 grams, we can set up the following equation: - Moles of chlorine + Moles of the other element = 100 grams / molar mass of the other element

Simplifying the equation, we get: - 21.85 grams / 35.45 g/mol + 78.15 grams / molar mass of the other element = 100 grams / molar mass of the other element

Solving this equation will give us the molar mass of the other element. Once we have the molar mass, we can determine the formula and valencies of the elements in the substance.

Unfortunately, without the molar mass of the other element, it is not possible to determine its formula and valency. If you have any additional information or if there is anything else I can assist you with, please let me know!