Answer:
The formula for the binary compound is HBr which get decomposes into hydrogen gas and bromine gas.
Step-by-step explanation:
Binary ionic compound : It is a type of compound that is made up of the ions of the two different elements in which one element is a metal and another element is a non-metal.
The binary compound that decomposes hydrogen gas and bromine gas is hydrogen bromide.The formula of hydrogen bromide is HBr.
According to reaction, 1 mole of hydrogen bromide decomposes into 1 mole of hydrogen and 1 mole of bromine gas.