2HI- gt H_(2)+I_(2) single replacement double replacement synthesis decomposition

The given chemical equation is:<br /><br />$2HI \rightarrow H_{2} + I_{2}$<br /><br />This equation represents the decomposition of hydrogen iodide (HI) into hydrogen gas (H2) and iodine gas (I2). In a decomposition reaction, a single compound breaks down into two or more simpler substances.<br /><br />Therefore, the correct answer is: decomposition.