I have say a 250cm3 liquid with a solid dissolved inside filled in a container. If I pour 50cm^3 of that liquid in another container, would the number of moles of the solid inside the 50cm^3 container be different to the number of moles in the original 250cm^3 container? I've been told the number of moles stays the same but to me, it makes sense to say that the moles have decreased because the number of particles of the dissolved solid has decreased. It would make sense to say that the concentration has stayed the same (the same amount of solid in a given volume). So which of the 2 values changes? The number of moles or the concentration?