Answers section
Questions 5.2
- What type of bond exists between lead and bromine in solid lead (II) bromide?
- What is the structure of lead (II) bromide? Explain.
- Write the formulae of lead ions and bromide ions, indicating their state symbols when molten.
- Which ions move to the anode and which ones move to the cathode?
- Explain why lead (II) bromide conducts electricity in molten state but not solid in solid state.
- Which of the following substances are also expected to conduct electricity in molten state but not as solids: H2O, NaCl, CS2, CuO, NH3, SiO2, Al2O3, PbI2?
Answers to Questions 5.2
- Ionic bond
- Giant ionic structure. Ionic bonds lead to structures that extend in all directions.
- Pb2+(l) and Br-(l) OR Pb2+(l) and 2Br-(l)
- Bromide ions (Br-) move to the anode; lead (II) ions (Pb2+) move to the cathode.
- In molten state, the positive lead (II) ions are separated from the negative bromide ions (ionic bonds broken); so they move about freely. In solid state, the ions are held together by strong ionic bonds; so they are not free to move about.
- NaCl, CuO, Al2O3, PbI2