The formation of CsCl from Cs(s) and Cl2(g) involves the following steps:
1. Cs(s)-Cs(g)
2. 1/2 Cl2(g)-Cl(g)
3. Cs(g) –Cs^+(g) + e^-
4. Cl(g) + e^- - Cl^-(g)
5. Cs^+(g) +Cl^-(g)-CsCl(s)
Which of these steps absorb energy and which release energy?
To determine which steps involve energy absorption and which steps involve energy release in the formation of CsCl from Cs(s) and Cl2(g), we need to analyze the changes in energy during each step.
1. Cs(s) - Cs(g): This step involves the conversion of solid cesium (Cs) into gaseous cesium (Cs). Breaking the metallic bonds between Cs atoms requires energy, so this step absorbs energy.
2. 1/2 Cl2(g) - Cl(g): This step involves the conversion of half a mole of gaseous chlorine (Cl2) into gaseous chlorine atoms (Cl). Breaking the covalent bonds between chlorine atoms also requires energy, so this step absorbs energy.
3. Cs(g) - Cs^+(g) + e^-: This step involves the ionization of gaseous cesium (Cs) into gaseous cesium cations (Cs^+) and the release of an electron (e^-). The ionization of atoms typically requires energy, so this step absorbs energy.
4. Cl(g) + e^- - Cl^-(g): This step involves the addition of an electron (e^-) to gaseous chlorine atom (Cl) to form a gaseous chloride ion (Cl^-). The addition of an electron to an atom typically releases energy, so this step releases energy.
5. Cs^+(g) + Cl^-(g) - CsCl(s): This step involves the combination of gaseous cesium cations (Cs^+) and gaseous chloride ions (Cl^-) to form solid cesium chloride (CsCl). The formation of an ionic solid typically releases energy, so this step releases energy.
In summary:
- Steps 1, 2, and 3 absorb energy.
- Steps 4 and 5 release energy.