An ideal gas differs from a real gas in that the molecules of an ideal gas have no attraction for one another. An ideal gas is defined as one in which collisions between atoms or molecules are perfectly elastic and in which there are no inter-molecular attractive forces. A real gas on the other hand is a gas that does not behave as an ideal gas due to interactions between gas molecules. Particles in a real gas have a real volume since real gases are made up of molecules or atoms that typically take up some space even though they are extremely small.
200 ml is 1/5 of a liter, so the answer is five times the number of moles present in the solution. 0.6 moles/0.2 liter = x moles/1.0 liter. Solving for x gives 0.2 x = 0.6 or x = 3.0 M
