# Tag Info

2

Air, fresh water, sea water, whiskey are fluid phases, aside of solid phases. A phase is a space region of homogenous properties of matter, possibly with gradient of theses properties (like sea water profile, or solution of statically dissolved solid), with strong discontinuity of these properties at the region boundary. The gradient can be at special ...

1

Consider three compositions: A. 2NaF + CaCO3 B. CaF2 + Na2CO3, and C. NaF + 0.5 CaCO3 + 0.5 CaF2 + 0.5 Na2CO3. Using data from the CRC Handbook (62nd ed), the heats of formation of A and B are respectively 560.47 and 560.6 kcal, so there is little driving force to make a reaction go to completion. Note that A should be near neutral pH, but B ...

0

I think it of this way. There is a lot of intermolecular space between individual molecules of a solvent. When we decrease the temperature, the individual molecules come closer, lose their heat of fusion and eventually the intermolecular spaces goes on decreasing until they became a tightly packed solid. Adding a solute hinders the process as the solute ...

2

Yes, the calcium ion could lead to precipitation. The solubility of $\ce{CaCO3}$ in distilled water is about 15 mg/L, which is about 0.15 mM calcium ion if there is no other source of carbonate. The solubility constant for $\ce{CaF2}$ is about $4\times 10^{-11}$, which means that we can only have 0.5 mM fluoride ions before precipitation will start. That's ...

5

Osmotic pressure for non-electrolytic solutes is given by $$\pi = CRT$$ where $C$ is the effective concentration of all the solutes. In our case, with multiple solutes, we simply add all their concentrations to obtain the effective concentration. This gives us \begin{align} \pi_\mathrm{cell} &= 0.05RT\\ \pi_\mathrm{environment} &= 0.03RT \end{... 4 Aside of dissolving iodine in ethanol, suggested in the other answer, another way is to reduce a part of iodine to iodide, e.g. by the classical reaction with thiosulphate. The rest of iodine will dissolve. The needed amount of thiosulphate is at least 1/3 of the stoichiometric amount wrt the total iodine.\ce{2 S2O3^2- + I2 -> S4O6^2- + 2 I-}\...

-1

Dissolve it in ethanol. Iodine I2 dissolves in ethanol to give a very well known solution sometimes called "tincture of iodine"1

1

Adding impurities(which mostly have low heat capacity, like salt) decreases the enthalpy of vaporization. This is because the impurities lower the heat capacity of the solution as a whole, making the enthalpy of vaporization lesser than the original solvent. This is why even though the boiling point of a solution increases when impurities are added it is ...

Top 50 recent answers are included