Why can't you have I M of H2O?

Question

jfraser · Answer

A 1M solution has to have some kind of solute dissolved in the solvent. H2O is a pure substance. If you take water and dissolve it in water, you have more water, not a solution of water.

anonymous · Answer

Thanks... That makes sense. My teacher tried to explain it mathematically and it just wasn't clicking

jfraser · Answer

if you thought of water as a solution of water in water, then you'd really have a "solution" of 55M H2O, because of the relationship of mass, volume, and density

1L of water weighs 1kg

1kg of water is 55.6moles of water
$$1000gH_2O * (\frac{1mol}{18g H_2O})$$ so 1L of water as a solvent, and 1kg of water as the "solute", then pure water has a "concentration" of 55.6M

anonymous · Answer

Thank you... Now that I see that 1 kg  is equal to 1 L it makes sense...