Solubility and Molarity

Maximum amount of solute has been dissolved in the solvent at that temperature
The solution has reached a state of equilibrium
Rate of dissolution = rate of crystallization (dissolving = crystalizing)
So, there is a constant concentration of solute dissolved in a saturated solution because the rate of dissolving/undissolving is the same
The maximum amount of solute that is dissolved in a saturated solution is different for every substance
One can measure the solubility of a substance by max grams of solute dissolved divided by 100g of water

More solute than is normally possible in a saturated solution
Unstable solution with more solute dissolved than a saturated solution at that temperature (above the curve but all dissolved)
To disturb, add a little extra solid, bend disk (release a tiny crystal), shake the solution
To make, heat up the solute-solvent mixture until all the solute dissolves then cool slowly (solid should stay dissolved unless disturbed)

For ionics/solids, as temp increases, solubility increases because more entropy
For covalents/gas, as temp increases, solubility decreases because freeing up gas/less entropy
For gases, as pressure increases, solubility increases (Henry’s law)

A measure of the concentration of a solution
Moles of solute per liter of solution
More moles dissolved per liter, more concentrated the solution
M = moles/L
Temperature dependent, when temp increases, volume increases
One uses volumetric flasks to make solutions with precise concentrations
Use M1V1 = M2V2 when we do not have a solid form of the substance we want to dissolve so we need a very concentrated solution from a chemical company to dilute it and get the molarity we want
Put it in the volumetric flask, fill to mark, shake to dissolve \n

Ice has a hexagonal structure
If particles get in the way/disrupt the formation then it is harder to freeze
So lower temp is needed
Freezing point of water is lower when the solution has a higher concentration of the same solute

The amount of a freezing point that goes down when a solute is added is not dependent on the identity of the solute but dependent on the concentration of solute particles
Higher molarity = lower freezing point

The amount the boiling point increases is not dependent on the identity of the solvent but is instead only dependent on the amount of solute
Higher molarity = highest boiling point
When more solute is added the boiling point increases

Solutions have more solute in them which makes it harder for water molecules to enter the gas phase.
The solution has a slower rate of evaporation and low vapor pressure (a measure of the tendency of a material to change into the gaseous or vapour state)
WHen solute particles are added some reach the upper layer of hte solution so the vapor pressure lowers due to the decrease in solvent molecules at the surface
Harder for water molecules to evaporate = more energy needed = higher bp

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Higher concentration means higher absorbance because the proportion of light that gets absorbed is affected by the number of molecules that it interacts with.
There are more molecules that interact with light

When a diver goes underwater, more nitrogen gas dissolves in his blood because Henry’s Law explains that during a dive any gases entering the blood are absorbed in the diver’s blood. There is an increase in solubility because higher pressure
When the diver comes up pressure decreases and volume increases. Bubbles form in the bloodstream because the gas is trying to escape.
Increased solubility of a gas at a higher pressure may have narcotic effects because there is too much nitrogen in the bloodstream.