Achemical reaction was used to separate a sample into its components what conclusion about the sample can be formed a it was a pure substance it was a compound bit was a heterogeneous mixture it was a homogeneous mixture

It was a compound, hence it needed to be separated into its individual components by chemical means.

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.