Question

ПОМОГИТЕ ПОЖЛУЙСТА. Расставьте степени окисления элементов в веществах с формулами: Р4, РН3, Р2О5, Н3РО4. Под формулами вещества запишите их название. Выпишите формулу того вещества, которое в хим. реакциях может являться только восст.и объясните причину

Answer 1

Oxidation States of Elements in Compounds

To determine the oxidation states of elements in compounds, let's examine the formulas provided and assign oxidation states to each element:

1. P4 (Phosphorus): - Phosphorus exists as a diatomic molecule in this case. - Since it is an element in its elemental form, the oxidation state of phosphorus is 0.

2. PH3 (Phosphine): - Phosphine is a compound consisting of phosphorus and hydrogen. - Hydrogen typically has an oxidation state of +1 in compounds. - To determine the oxidation state of phosphorus, we can assign x to it. - Since the overall charge of the compound is neutral, the sum of the oxidation states must be zero. - Therefore, 1(x) + 3(+1) = 0, which gives us x = -3. - The oxidation state of phosphorus in PH3 is -3.

3. P2O5 (Phosphorus Pentoxide): - Phosphorus pentoxide is a compound consisting of phosphorus and oxygen. - Oxygen typically has an oxidation state of -2 in compounds. - To determine the oxidation state of phosphorus, we can assign x to it. - Since the overall charge of the compound is neutral, the sum of the oxidation states must be zero. - Therefore, 2(x) + 5(-2) = 0, which gives us x = +5. - The oxidation state of phosphorus in P2O5 is +5.

4. H3PO4 (Phosphoric Acid): - Phosphoric acid is a compound consisting of phosphorus, hydrogen, and oxygen. - Hydrogen typically has an oxidation state of +1 in compounds. - Oxygen typically has an oxidation state of -2 in compounds. - To determine the oxidation state of phosphorus, we can assign x to it. - Since the overall charge of the compound is neutral, the sum of the oxidation states must be zero. - Therefore, 1(x) + 3(+1) + 4(-2) = 0, which gives us x = +5. - The oxidation state of phosphorus in H3PO4 is +5.

Based on the provided compounds, the oxidation state of phosphorus can be either -3 or +5 in chemical reactions. The reason for this is that phosphorus can undergo both reduction and oxidation reactions, depending on the specific reaction conditions and the other elements involved.