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Yes it is called ''Star rule (method)'' in Albanian ''rregulla e yllit''. We use this method too.


$\Delta H_\mathrm{vap} \gt 0$ is valid regardless of the relation $T$ vs $T_\mathrm{vap}$, as it is an endothermic process, requiring energy to break intermolecular bonds. Its value drifts with T, depending on the relation of the specific/molar heat capacity of the liquid and the vapour, following the Hess's Law. You probably confuse $\Delta H_\mathrm{vap}$ ...


Poutnik is right, what likely happened is one or both of the reagents lost its potency through chemical reactions to which they are susceptible. In the case of the sodium hydroxide, if it reacted with carbon dioxide from the air (it is best stored and handled under a CO2-free atmosphere), the resulting carbonate is no longer a strong enough base to react ...


From Wikipedia: Osmolarity = osmolality * (ρsol − ca) where: ρsol is the density of the solution in g/ml, which is 1.025 g/ml for blood plasma.[5] ca is the (anhydrous) solute concentration in g/ml – not to be confused with the density of dried plasma p.s. I am surprised that the osmolarity and osmolality differ that much in numeric value. For other (non-...

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