Solid added to liquid and the solid floats down to bottom of container physical or chemical change?

What is the molecular formula of a hydrocarbon with m+ = 166? (write the formula with no subscripts, e.g. c4h10.) what is the sum of rings and double bonds in this compound?

In vapor-liquid equilibrium in a binary mixture, both components are generally present in both phases. how many degrees of freedom are there for such a system? the reaction between nitrogen and hydrogen to form ammonia occurs in the gas phase. how many degrees of freedom are there for this system? steam and coal react at high temperatures to form hydrogen, carbon monoxide, carbon dioxide, and methane. the following reactions have been suggested as being involved in the chemical transformation:

How can a mixture of salt water be separated into salt and water