<p>Chemistry Name : Worksheet : Ch. 20-21 ; Obj. 1-5 Date :</p><p>A. Read pp. 631-635 and answer the following questions.</p><p>1. ______reactions are chemical reactions in which electrons are transferred between reactants.</p><p>2. ______reactions are another name for the above reaction.</p><p>3. Put a check next to the following reactions which are redox reactions.(Hint : Ions must be formed as electrons are transferred. Redox reactions are not just the simple combining of already existing ions).</p><p>3+ - _____ Fe + 3 Cl -----> FeCl3 _____ S + O2 ------> SO2 _____ Cl2 + H2 -----> 2 HCl 4+ 2- _____ Pb + 2 O ------> PbO2</p><p>4. Give two common examples of oxidation reactions which we might observe in our lives.. </p><p>5. Match the characteristics of the process of oxidation and reduction.</p><p> a. oxidation b. reduction</p><p>_____ the gaining of electrons in an ionic reaction</p><p>_____ the loss of electrons in an ionic reaction</p><p>_____ the gaining of oxygen</p><p>_____ the loss of oxygen</p><p>_____ the loss of a hydrogen atom by a covalent compound</p><p>_____ the gaining of a hydrogen atom by a covalent compound</p><p>_____ causes an increase charge on an ion (more positive or less negative)</p><p>_____ causes a decrease in the charge on an ion (less positive or more negative)</p><p>_____ occurs when a magnesium atom becomes a magnesium ion with a 2+ charge.</p><p>_____ occurs when sulfur atom becomes a sulfide ion (2- charge).</p><p>_____ occurs when electrons shift toward an atom with a higher electronegativity in a covalent bond</p><p>_____ occurs when electrons shift away from an atom with a lower electronegativity in a covalent bond 6. _____(T/F) Reduction reactions and oxidation reactions seldom occur together. 7. ______are substances in redox reactions which donate (lose) electrons.</p><p>8. ______are substances in redox reactions which accept (gain) electrons.</p><p>9. _____ (T/F) The reactant reduced in a redox reaction is also the reactant which is the oxidizing agent.</p><p>10. _____ (T/F) The reactant which is oxidized in a redox reaction is also the reducing agent.</p><p>11. Identify the reactants which are reduced and the reactant which is oxidized and which reactant is the reducing agent and which reactant is the oxidizing agent in each reaction below.</p><p> a. 2K + F2  2KF</p><p>_____ oxidized reactant</p><p>_____ reduced reactant</p><p>_____ reducing agent(reactant)</p><p>_____ oxidizing agent (reactant)</p><p> b. 4 Al + 3O2  2 Al2O3</p><p>_____ oxidized reactant</p><p>_____ reduced reactant</p><p>_____ reducing agent(reactant)</p><p>_____ oxidizing agent (reactant)</p><p> c. Mg + I2  MgI2</p><p>_____ reducing agent(reactant)</p><p>_____ oxidizing agent (reactant)</p><p>_____ oxidized reactant</p><p>_____ reduced reactant</p><p> d. 2 Al + 3 Cl2  2 AlCl3</p><p>_____ oxidized reactant</p><p>_____ reduced reactant _____ reducing agent(reactant) _____ oxidizing agent (reactant)</p>