Question

Как расставить индексы если по валентности и СО это невсегда можно сделать. Например Al+O2=AlO у AL Валентность 3 у O 2 Нок 6 значит Al2O3. Но вот в Sn+O2=SnO вроде должно быть 2SnO но SnO2 Почему так? Как определять валетность тогда у Sn? У Sn может быть две валентности 2 и 4 так как их определять ?

Answer 1

Ответ:

Дело в том, что большинство металлов имеют валентность от 1  до 2, а амфотерные еще и до 3, в составе кислот и оксидов амфотерные металлы могут проявлять валентность 7+, например хром: Cr2O7

Answer 2

Valency and Indexing in Chemical Equations

When it comes to balancing chemical equations, the valency of elements plays a crucial role. Valency refers to the combining capacity of an element, or the number of electrons an atom can gain, lose, or share to form chemical bonds. In some cases, it is possible to determine the valency and balance the equation based on the valency rules. However, there are situations where it may not be straightforward to determine the valency and balance the equation using valency alone.

Let's consider the examples you provided:

1. Al + O2 = AlO: In this case, aluminum (Al) has a valency of 3, and oxygen (O) has a valency of 2. To balance the equation, we need two aluminum atoms to combine with three oxygen atoms, resulting in Al2O3. The valency of aluminum is determined based on its position in the periodic table and its electron configuration.

2. Sn + O2 = SnO: In this case, tin (Sn) can have two valencies, 2 and 4. The valency of an element can vary depending on the compound it forms. In this equation, tin is exhibiting a valency of 2. Therefore, to balance the equation, we need two tin atoms to combine with one oxygen atom, resulting in SnO. The valency of tin in this case is determined based on the overall charge of the compound and the known valency of oxygen.

It is important to note that determining the valency of an element in a specific compound requires knowledge of the compound's overall charge and the valencies of other elements involved. The valency of an element can vary depending on the specific compound it forms.

In some cases, experimental data or additional information may be needed to determine the valency of an element in a particular compound. This can include analyzing the oxidation states of the elements or considering the electronegativity differences between the elements involved.

In summary, while valency is an important factor in balancing chemical equations, it may not always be sufficient to determine the valency and balance the equation. Additional information and considerations, such as the overall charge of the compound and the known valencies of other elements, may be necessary to determine the valency of an element in a specific compound.