Bromine is an element in Group 7 of the Periodic Table.
State the number of outer-shell electrons in an atom of bromine.
Identify an element in Group 7 that is a solid at room temperature.
Identify an element in Group 7 that is more reactive than bromine.
Bromine is formed by the electrolysis of molten lead(II) bromide, PbBr2\text{PbBr}_2PbBr2. During this process, electrode A\text{A}A is the negative electrode (cathode) and electrode B\text{B}B is the positive electrode (anode).
Explain why solid lead(II) bromide does not conduct electricity, whereas molten lead(II) bromide does.
During electrolysis, brown fumes of bromine gas are observed at electrode B\text{B}B. The ionic half-equation for this reaction is:
2Br−→Br2+2e− 2\text{Br}^- \rightarrow \text{Br}_2 + 2\text{e}^- 2Br−→Br2+2e−Why is this reaction described as oxidation?
Write an ionic half-equation for the reaction at electrode A\text{A}A and describe the appearance of the product that forms on this electrode.
Potassium bromate is a compound containing potassium, bromine, and oxygen. A sample of potassium bromate is analyzed and found to contain 3.9 g3.9\text{ g}3.9 g of potassium, 8.0 g8.0\text{ g}8.0 g of bromine, and 4.8 g4.8\text{ g}4.8 g of oxygen. Calculate the empirical formula of this compound. [Relative atomic masses, ArA_rAr: K=39\text{K} = 39K=39; Br=80\text{Br} = 80Br=80; O=16\text{O} = 16O=16]
