תגובות חמצון -חיזור ודוגמאות מחיי היום יום מהי תגובת חמצון –חיזור? In an oxidation–reduction reaction, electrons are transferred from one substance to another. if one substance loses electrons, another substance must gain electrons. energy is provided to us from food. electrical energy is provided in batteries. iron rusts. דוגמאות

Transfer of Electrons תגובת חמצון ותגובת חיזור In oxidation–reduction reactions, the process of losing electrons is called oxidation. Oxidation Is a Loss of electrons. (OIL) the process of gaining electrons is called reduction. Reduction Is a Gain of electrons. (RIG)

תגובת חמצון ותגובת חיזור

דוגמאות

השינויים במטען האטום בתגובת חמצון ובתגובת חיזור

דוגמא לתגובת חמצון חיזור- יצירת סידן גופרי In the reaction: the reactant, Ca has a charge of 0 and the product, CaS contains a Ca2+ ion. calcium loses two electrons, meaning oxidation has taken place. the reactant, S has a charge of 0 and the product, CaS contains an S2− ion. sulfur gains two electrons, meaning reduction has taken place.

המשך Adding the two reactions, oxidation and reduction, gives us the overall reaction. The overall reaction is written as:

המשך Zn and Cu2+ When zinc is added to copper(II) sulfate, zinc undergoes oxidation, while copper undergoes reduction. Blue orange

Electron Transfer from Zn to Cu2+ המשך Electron Transfer from Zn to Cu2+ Oxidation: electron loss Reduction: electron gain

1 תרגיל Learning Check Identify each of the following reactions as oxidation or reduction.

פתרון 1 Solution Identify each of the following reactions as oxidation or reduction.

תרגיל 2 Learning Check In light-sensitive sunglasses, UV light initiates an oxidation-reduction reaction. 1. Which reactant is oxidized? 2. Which reactant is reduced?

פתרון 2 Solution In light-sensitive sunglasses, UV light initiates an oxidation-reduction reaction. 1. Which reactant is oxidized? Cl− 2. Which reactant is reduced? Ag+

תרגיל 3 Learning Check Identify the substances that are oxidized and reduced in each of the following reactions.

3 פתרון Solution Identify the substances that are oxidized and reduced in each of the following reactions. 1. Mg is oxidized. Mg(s) Mg2+(aq) + 2e− H+ is reduced. 2H+(aq) + 2e− H2(g) 2. Al is oxidized. 2Al(s) 2Al3+(s) + 6e− Br is reduced. 3Br2(l) + 6e− 6Br−(s)

תרגיל 4 Write the separate oxidation and reduction reactions for the following equation. 2Cs(s) + F2(g) 2CsF(s) A cesium atom loses an electron to form cesium ion. Cs(s) Cs+(s) + 1e− oxidation Fluorine atoms gain electrons to form fluoride ions. F2(s) + 2e- 2F−(s) reduction

חמצון חיזור במערכות ביולוגיות- חשוב מאוד In biological systems, oxidation may involve the loss of H or the gain of O. In biological systems, reduction may involve the gain of H or the loss of O.

חמצון חיזור במערכות ביולוגיות

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