The given road map problem is 
As compound ' X ' produces a colorless gas ' Y ' with rotten fish smell, it can be Ca3P2 (calcium phosphide). The reaction takes palce as follows : Ca3P2+H2O⟶Ca(OH)2+PH3 Colorless gas with rotten fish smell. ' Y ' CuSO4+Y′PH3⟶Cu3P2+H2SO4