NEED HELP WITH THIS ASAPPP

When will le chatelier's principle come into effect? at the beginning of a reaction, when there are only reactants when a reaction has reached chemical equilibrium when a catalyst is added to a reaction mixture when a reaction is occurring but not yet at equilibrium

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure

Calculate the concentration of all species in a 0.165 m solution of h2co3.