Electrolysis

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Question 12
Medium

This question is about the industrial extraction of calcium metal and bromine gas through the electrolysis of molten calcium bromide (CaBr2\text{CaBr}_2CaBr2​).

a.

Calcium is deposited at the negative electrode. Describe what happens to calcium ions (Ca2+\text{Ca}^{2+}Ca2+) during this process in terms of electrons.

[1]
b.

Write a balanced half-equation to represent the formation of bromine molecules (Br2\text{Br}_2Br2​) at the positive electrode from bromide ions (Br−\text{Br}^-Br−).

[1]
c.

The overall chemical equation representing this electrolysis process is: CaBr2→Ca+Br2\text{CaBr}_2 \rightarrow \text{Ca} + \text{Br}_2CaBr2​→Ca+Br2​ Determine the mass, in kg\text{kg}kg, of bromine gas generated when 500 kg500\text{ kg}500 kg of molten calcium bromide is completely decomposed.

Relative atomic masses (ArA_rAr​): Ca=40\text{Ca} = 40Ca=40; Br=80\text{Br} = 80Br=80

[3]

Electrolysis Questions

  1. GCSE
  2. /Chemistry
  3. /Electrolysis