chemical reactions spontaneously occur when the free energy of the products is the free energy of the reactants

The covalent compound acetylene, which is the fuel of the oxyacetylene torch used by welders, has the molecular formula c2h2. the covalent compound benzene, a commercial solvent, has the molecular formula c6h6 each of these covalent compounds contains carbon and hydrogen atoms in a one-to-one ratio. would it be correct to write the chemical formulas of each as ch? explain.

In which phase(s) do the molecules take the shape of the container?

What is the percentage of hydrogen in c2h4