Hydration of alkynes using Brönsted acidic ionic liquids in the absence of Nobel metal catalyst/H2SO4

► Several imidazole based Brönsted acidic ionic liquids (BAILs) were developed. ► Hydrogen bonding plays a key role in tuning the acidity of ionic liquids. ► Ionic liquids can be recycled without significant loss in catalytic activity. ► BAILs having more number of SO3/SO3H functionalization exhibited higher activity. ► Activation energy of the rate-limiting step was calculated using DFT calculations.