Can anyone explain to me how is the molar concentration, or should I say the number of moles of water equal to 55.5? I need it with some explanation.

Question

Wyatt Adkins · Accepted Answer

Yes, one liter of water does contain 55.5 moles of water.

Using the density and molar mass of water, you can calculate the number of moles that are contained in one liter of water. The mass of one liter of water at room temperature will be equal to the approximate density of one gram per milliliter, or 1 g/mL. #1cancel("L") * (1000cancel("mL"))/(1cancel("L")) * "1 g"/(1cancel("mL")) = "1000 g"# Water's molar mass, which indicates how much one mole of water weighs, can be used to calculate how many moles this amount of water would contain. #1000cancel("g") * "1 mole water"/(18.01528cancel("g")) = "55.5 moles"# Regardless of whether you're talking about moles of solute or not, molarity is defined as moles per liter, so you can say that the molar concentration of water is equal to #C_"water" = n/V = "55.5 moles"/"1 L" = "55.5 M"#

Serenity Allen · Answer

undefined The molar concentration of water is 55.5 mol/L at room temperature and pressure because this is the concentration at which the density of water is highest. This corresponds to the molar mass of water, which is approximately 18 grams per mole. Therefore, 1 liter of water contains approximately 55.5 moles of water molecules.