The structural, electronic, optical, and thermodynamic properties of hydrogenated silicene (silicane) in three stable structures, viz. chair (C), boat (B), and tricycle (T), are studied using first-principles calculations. The band structure and density of states are discussed. The stability is analyzed using binding energy and phonon calculations. Silicane is highly temperature sensitive compared with silicene. The optical properties are studied for parallel (E perpendicular to c) and perpendicular (E parallel to c) polarization of the electric field in the energy range of 0-20 eV. Four parameters, namely the dielectric constant epsilon(0), refractive index n(0), birefringence Delta n(0), and plasmon energy (omega(p)), are calculated for the first time. The calculated values are in good agreement with available reported values.