Which solute is least soluble in water and why? and why aren't the others(so i understand)?
methanol, ethanol, and 1-propanol are all totally miscible with water in all proportions. 1-butanol does have limited solubility in water (up to 73 grams/Liter) because it has a longer carbon chain, which makes it more lipophilic (oil loving) than the others which all have smaller carbon chains.
Which is least soluble in water and why?
Either you're a senior taking inorganic chem, or your instructor *really* hates you. Maybe both. Bad luck. The general chemistry explanation: Water is a polar protic solvent, so the least polar molecule will be the least soluble. It will huddle with its kind, held together by van der Waal forces like all nonpolar molecules, while the water hydrogen bonds with itself and tries to ignore the clump of nonpolar invader in its midst. This really doesn't help except to convince you that CO is the most soluble (which is wrong). The "elbow room" explanation: All these molecules are really small, except for chlorine, and all of them have non-bonding pairs which can't help but be attracted to the partial-positive charge on water's hydrogen atoms. More non-bonding pairs means more opportunity to bind (reversibly) water and be solvated. Smaller (electronic) size means fewer water molecules can elbow their way in and solvate the molecule. Looking at your molecules this way: 1. Cl2 is the most soluble. It has three nonbonding pairs at each end, and it's really big compared to the the others. Plenty of parking for any HOH that cares to stop by. 2. CO2 is the next most soluble, followed by CO. The partial positive charge on C is greater in CO2 than in CO because two oxygens are pulling electrons away from it, and CO2 has 4 nonbonding electron pairs separated by two bond lengths versus CO's 2 nonbonding electron pairs separated by one bond length. 3. CO is less soluble than CO2, as explained in (2) 4. O2 and N2 are the least soluble. They are both nonpolar, with no partial positive or negative charge like CO2. The OO double bond is slightly longer than the NN triple bond, but I feel that the four nonbonding pairs of O2 is what makes it more soluble than N2 with only two nonbonding pairs. 5. N2 is the least soluble as explained in (4) HOWEVER, I wouldn't be surprised to learn that I'd misplaced one or two of these. Which is why I believe your instructor hates you.
How do you determine what is least soluble in water?
Well, see for a substance to dissolve in water, the forces in water must be strong enough to overcome the forces of the substance. Water's major forces (intermolecular forces) are hydrogen bonding and dipole-dipole interactions. Now, looking at the listed compounds you have, there is a trend in the strength of the atoms (and polyatomic ions) that hold a molecule of the compound together. Smaller and greater charges can hold together better. You can see that Ca is smaller than Potassium, so the compounds that have potassium are out of the picture. Now, compare the charges of phosphate to nitrate. Phosphate is a 3- and nitrate is a 1-. Now, the charge of the phosphate outweighs that of the nitrate, so there is a stronger attraction between calcium and phosphate than between calcium and nitrate. So water can more easily separate the Ca(NO3)2 than the Ca3(PO4)2. By the way, the rule of smaller atoms and larger charges are stronger is a formal law, but the name of it is slipping my mind right now.
Most alcohols that are liquids at room temperature are miscible with water (rather than soluble, as there’s no clear way to distinguish which is the solvent and which the solute), as both they and water are polar & protic in nature (dielectric constants of water & ethanol are 88 & 24.55 respectively). The hydroxyl group in aliphatic alcohols easily form hydrogen bonds with water molecules, so most will mix happily.
Which of the following would be LEAST soluble in water?
I think it's Br2. "Like dissolves like." So polar substances dissolve in polar substances. Water is polar and Br2 is non-polar.
There are more than two gases which are insoluble in water. The only criteria for a gas to have very little solubility in water is for its intermolecular forces to be only London Dispersion Forces (LDFs) or perhaps very weak dipole-dipole forces.This is because for a substance to be soluble in another substance, the primary requirement is that the two substances have similar intermolecular forces. That way, when the bonds between solute molecules and solvent molecules are broken to form bonds between the two, the net change in enthalpy ([math]\Delta \text{H}[/math]) will be close to zero and the increased entropy ([math]\Delta \text{S}[/math]) from greater molecular configurations if dissolved will cause the dissolution reaction to proceed spontaneously.For this reason, if two substances have very different intermolecular forces, the enthalpy change will be significantly positive for the dissolution reaction and thus it will not occur spontaneously to any significant degree.Therefore a method of guaranteeing that a gas will be insoluble in water is to check its polarity: if it is nonpolar, it will only experience LDFs; otherwise, it will experience dipole-dipole forces and will be significantly more likely to dissolve. Examples of this include[math]\begin{align} \boxed{ \text{H}_2 \text{, } \text{O}_2 \text{, } \text{Ar} \text{, } \text{Ne} \text{, } \text{CCl}_4 \text{, }\dots} \end{align} \tag*{}[/math]The following image explains the dissolution process and justifies why, for a reaction to have an enthalpy less than or close to zero, the solution particles must be very strongly bonded, as the energy to form the solution bond must be close to the sum of the energy to break the solvent and solute bonds (recall that breaking bonds is endothermic and thus forming them is exothermic).[1]Footnotes[1] 11.1 The Dissolution Process
Not all organic compounds are insoluble in water. For example, ethanol is an organic compound, though it is highly soluble in water. Ethanol is even soluble in organic compounds.Remember-“LIKE DISSOLVE LIKE”This means polar compounds are soluble in polar solvents and non-polar in non-polar solvents.Generally organic compounds are non-polar so, most of them are insoluble in water as water is a polar solvent.In case of ethanol, it contains polar O-H bond. Hence it is soluble in water. But it is not as polar as water and hence it readily dissolves in non-polar solvents too like ethers.The soap we use in daily life too is made up of long carbon chain. Even then, it dissolves in water. It is because of one ionic bond at the end of the chain. There is sulphonic acid ([math]SO_3H-)[/math] group attached to one end of carbon group. This group is hydrophilic (water loving) and hence accounts for dissolution of soap in water.
Hydrophile liquids. Liquids with hydrogen bonds between their molecules are soluble in water and are called hydrophile liquids.
As a general rule, like dissolves like. It means polar substances dissolves in polar and non polar in non polar. As water is highly polar in nature, polar substances dissolves easily in it but non polar dissolves in very less amount. The polar nature of water is due to large difference in electronegativity of oxygen and hydrogen atoms in a water molecule and substances dissolves in it mainly due to hydrogen bonding.