Problem we did in class 1/27

[Brian_Ho_2B]

We found that the mass of water was 0.100g based on the fact that 0.050M HCl reacted with 0.050M NaOH in 1.0L. However, that neutralization reaction would've produced 0.050 mol H20 and 0.050mol NaCl. Why did we make the bold approximation of having water equal to 0.100 L when based on the stoichiometric ratios, it was more like 0.050L because of the amount of moles?

[Brian Tangsombatvisit 1C]

My explanation would be that the resulting solution is not 100% pure water (it has salt in it), but the total volume of the products is still 100 mL; when we are finding the volume of water we are assuming that it is the total volume of the solution after the neutralization reaction. I guess Dr. Lavelle made the assumption that the amount of salt produced was negligible in terms of the change in density it had on water. It's also important to remember that acids and bases are aqueous, so they too are dissolved in water.