Use the periodic table to determine the molar mass of each of the following elements. Use the correct number of significant figures. Potassium (K):
g/mol
Osmium (Os):
g/mol
Manganese (Mn):
g/mol

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.

Solubility would be your answer.