Question

For two questions below, first write and balance the equation for the chemical reaction. Please, also review the material in Chapter 8, if you will feel you might need it in order to answer the questions. Next, please answer the following questions:

(a) What substance is reduced?

(b) What is the reducing agent?

(c) What substance is oxidized?

(d) What is the oxidizing agent?

Question 1:   Erbium metal (Er) can be prepared by reacting erbium(III) fluoride with magnesium; the other product is magnesium fluoride.

Question 2: Europium (Eu) is used in older television screens to give a red color. The metal can be prepared by electrolysis of molten europium(III) chloride; chlorine gas is a by-product.

Answer 1

Q1. The balanced reaction is : 2 ErF₃ + 3 Mg $\rightarrow$ 2 Er + 3 MgF₂

(a) Substance reduced = Er

(b) reducing agent = Mg

(c) substance oxidized = Mg

(d) oxidizing agent = ErF₃

Q2. The balanced reaction is : 2 EuCl₃$\rightarrow$ 2 Eu + 3 Cl₂

(a) Substance reduced = Eu

(b) reducing agent = EuCl₃

(c) substance oxidized = Cl

(d) oxidizing agent = EuCl₃