For a certain reaction at \( 300 \, \text{K} \), \( K = 10 \), then \( \Delta G^\circ \) for the same reaction is __________ \( \times 10^{-1} \, \text{kJ mol}^{-1} \). (Given \( R = 8.314 \, \text{J K}^{-1} \text{mol}^{-1} \) )