NaCl polar substances are soluble in polar solvents waterbut insoluble in non-polar solvents benzene, ethoxyethane, 1,1,1-trichloroethane Alkanes non-polar substances are soluble in non-polar solvents benzene, ethoxyethane, 1,1,1-trichloroethane Hi Mendy! The principle you mention is not only a rule, but it has an explanation. By the way, in science there is always an explanation for rules, or facts.

It could be that the scientists of today do not know all the facts explanation, what does not mean that the scientists of tomorrow will not find an explanation, or hopefully the explanation, if it is correct. It has to do with the chemical bonds.

Broadly speaking, the chemical bonds can be ionic or covalent. So the crystalline solids are held together by the attraction of 2 oppositely charged ions ionic bond.

Another way of bonding, the covalent bond occurs when the bond is formed by a shared pair of electrons. There are other in between cases where the electron sharing is not equal, and it occurs some part that is slightly positive.

In these cases, where the electron sharing is not equal, the bond is called a polar covalent bond, or simply a polar bond and in the cases where electrons are equally shared are called non polar covalent bonds.

Then coming back to the solubility rule, non polar or slightly polar solutes dissolves best in polar solvents. The rule works well in this case.

like dissolves like

So fats, oils and greases that are non polar or slightly polar dissolve well in non polar solvents as benzene. That happens because the forces that hold non polar molecules together are mostly weak. So, the amount of energy needed to separate the atoms at the molecules of the solute and to break the attractive forces between molecules of the solvent are small.

So there are a dissolution or a solution is formed. But the rule that likes dissolves likes does not works so well for polar substances and, in particular, for aqueous solutions. The water solubility has to do with the ability of water to form hydrogen bonds to the solute molecules.How does the nature of the molecule, polar or non-polar, affect its solubility in water, the universal solvent? Students interact with molecular models created via Molecular Workbench to make predictions, observations and conclusions about dissolving and polarity.


Students then extend their thinking with a final activity listed below. Students will use molecular models that demonstrate how water dissolves substances and how nonpolar substances are not attracted to water molecules. Students explain results and then are asked to extend their thinking by predicting which substances will dissolve in water based on there structure.

When a ruler is charged, has static electric charges, is placed near a stream of water the water is attracted to the ruler.

The water "bends", due to its polarity! See the link below for the interactive resource. You are impersonating. Stop Impersonating. Web-based Content. Grade Levels. Course, Subject. Options Printer Friendly Version Email. Related Academic Standards. Relate the physical properties of matter to its atomic or molecular structure. Compare properties of solutions containing ionic or molecular solutes e.

like dissolves like

Describe how chemical bonding can affect whether a substance dissolves in a given liquid. What is meant by the expression "Like dissolves like"? Will all solvents dissolve all solutes? Why is rubbing alcohol miscible in water, while cooking oil is not? Content Provider. Date Published.

February 19, Please waitBy using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. It only takes a minute to sign up. Polar solvents love polar solutes to be dissolved in it and non polar with non polar. Often said as like dissolves like. Okay, polar loving polar can be understood with help of the facts: same polar nature, same kind of interactions etc. The reason behind this is the hydrophobic effect.

Everyone has seen it if they pour a spoonful of vegetable oil into a pot of water, e. As long as nothing is disturbing the vegetable oil, it will collect itself together in one big bubble rather than form many small bubbles.

Polar solvents will always be arranged in a way that positively polarised areas are close to negatively polarised areas in the neighbouring solvent molecule. Hydrogen bonds — especially in water — are nothing but the extension of this concept to even more polarisation. Polar molecules, as you stated, will fit together with this scheme well.

Unpolar compounds mixed in do not. As soon as you add an unpolar compound to a polar solvent, you are creating a type of artificial boundary and only the areas of the solvent molecules that are neither particularly positive or negative will be happy to be in the near vicinity.

That means that you have a much higher ordering of the solvent molecules where they hit an unpolar compound, because one direction is basically doomed to be neither positive nor negative. However, it will also have almost the same thickness, no matter how big the contained part is. Therefore, if multiple unpolar molecules clump together, the overall number of polar molecules constrained in that wall is lower — an entropic gain.

Thus, unpolar compounds tend to either not dissolve or precipitate out of polar solvent solutions. This also works in the opposite direction. A polar molecule will prefer, for energetic reasons, to have a polar neighbour. However, an unpolar solvent cannot provide that polar environment.

A neighbouring undissolved polar molecule, however, can. Here again, the polar compounds rather stay clustered together as it allows the central molecules to be more disordered while only a small layer on the border must take care to interact as well as possible with the unpolar solvent.

In reality, most compounds are somewhere on a scale from absolutely unpolar to very polar and are able to adapt to a wide range of organic solvents. Conversely, some organic solvents have the reputation of dissolving almost anything organic; most notably dichloromethane. However, the solubilities may greatly vary. I would be quite dubious in ascribing much validity to answers which use the word "unpolar", since that word indicates either a lack of familiarity with chemical terminology or a lack of respect for it.

The way I consider solvation for two pure chemical compounds is that in their pure state the interactions are between molecules of themselves.

These interactions can be either weak or strong and this can be determined using Thermodynamic experimentation. When considering solubility, the added term is the A2B interactions. When A2A and B2B interactions are weak, then even weak A2B interactions should result in substantial interactions and hence substantial mixing. When A2A and B2B interactions are both strong, A2B interactions must also be strong to get a homogeneous equilibrium phase.

So we should look at these interactions relative to the strongest. If A2A interactions are strong say NaCl and B2B interactions are weak say n-hexane then we'd predict that the A2B interactions are also going to be very weak, and that the solubility of NaCl in hexane is going to be small negligible, actually.

So in this case the strong interaction in the non solute NaCl dominates. But instead of NaCl, consider C 20 H 42 mixed into n-hexane.Feel free to accept your comment. Spam comment will be deleted and blocked. Skip to content.

Pernah dengar istilah ini? Yak, mungkin bagi sebagian yang dibesarkan di ranah scientis telah akrab dengan istilah niy.

like dissolves like

Bagi yang berada di wilayah2 non-sains, tentu saja akan menjadi asing. Baiklah, akan kujelaskan sejenak. Like dissolve like. Sebuah prinsip kelarutan di mana, suatu zat hanya akan larut pada pelarut yang sesuai. Dengan kata lain, zat yang bersifat polar akan larut pada pelarut polar dan suatu zat non polar pun akan larut pada pelarut yang non polar. Prinsip ini dikenal dnegan prinsip like dissolve like. Lalu, kalau dalam dunia perubatan, prinsip ini juga berlaku. Untuk obat2 yang larut dalam air, maka hanya dapat digunakan air sebagai pelarut.

Takkan pernah ada di dunia ini obat yang larut dalam air lalu kemudian digunakan minyak sebagai pelarutnya. Karena, sampai kapan pun zat tersebut tidak akan dapat larut. Sampai kapanpun, air takkan dapat bercampur dengan minyak. Ini pengecualian untuk ubat-ubatan yang dibikin pelarut campur macam eliksir, atau suspensi, ataupun emulsi nih yaaa lha, wong sediaan macam ni ditambahkan zat pembantu tho.

Kemudian, kita amati suspensi. Apa itu suspensi? Suspensi adalah bentuk obat cair kalau masyarakat umum mengenalnya sebagai obat sirup saja yang di dalamnya terdapat zat aktif yang tidak larut dalam air sehingga dirancang sedemikian rupa, yang kemudian dapat larut dalam pengocokkan.

Jika dibiarkan dalam jangka waktu lama, tetap akan terjadi pemisahan, ada yang bagian endapan, ada pula yang bagian larutannya. Apa contoh? Semacam Susu Mylanta untuk maag. Atau, jika teman2 bersedia untuk kembali ke masa lalu sejenak, maka ingat-ingatlah, dahulu waktu kecil dikasi obat sirup, tapi, warnanya putih kayak serbuk susu yang dikocok dengan air itu looh nggak beningyang didalamnya ada obat-obatan serbuk juga.

Nah, itulah yg disebut suspensi. Lalu…lalu…, memangnya kenapa? Hihihi… Okeh. Jika kita perhatikan, prinsip like dissolve like ini sebenarnya juga tengah terjadi pada diri kita loooh. Sederhana saja. Kita lihat dari kecendrungan seseorang dalam memilih teman. Pernahkah kita perhatikan, teman angkatan misalnya, secara disengaja atau tidak seolah-aoalh ada pengelompokkan-peneglompokkan. Lain pula dengan si R. Okelah memang kita semua berteman secara keseluruhan, tapi, tetap ajah ada kecendrungan untuk dekat dengan orang-orang tertentu.

Ini analog dengan suspensi, yang pada pengocokkan akan bercampur menjadi larutan homogen. Lalu, jika dibiarkan agak lama, pada zona aman, masing-masing akan memilih sesuai dengan kecendrungannya.

Kalo dalam suspensi, sebagian menjadi endapan, sebagian lagi menjadi larutan. Begitu pun halnya dengan kita.These metrics are regularly updated to reflect usage leading up to the last few days. Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts. The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online.

Clicking on the donut icon will load a page at altmetric. Find more information on the Altmetric Attention Score and how the score is calculated. This paper describes a demonstration and a straightforward experiment using the guided-inquiry approach for the "like dissolves like" principle that is implemented at the beginning of the academic year.

This experiment extends the students' understanding of the concept of solubility of organic molecules and its relationship to chemical structure. It is also a stepping stone to their comprehension of separation techniques for organic compounds. The objective of this experiment is to observe how the solubility of alcohols varies in water, acetone, or hexane.

This approach allows students to integrate different concepts of organic chemistry learned throughout the general chemistry course. These concepts include: covalent bond, dipole moment, molecular geometry, intermolecular forces, and solubility. The American Chemical Society holds a copyright ownership interest in any copyrightable Supporting Information. Files available from the ACS website may be downloaded for personal use only.

Users are not otherwise permitted to reproduce, republish, redistribute, or sell any Supporting Information from the ACS website, either in whole or in part, in either machine-readable form or any other form without permission from the American Chemical Society.

For permission to reproduce, republish and redistribute this material, requesters must process their own requests via the RightsLink permission system. View Author Information. Cite this: J. Article Views Altmetric .Will all solvents dissolve all solutes? Types of substances that form solutes and solvents Dipoles Polar solvents Non-polar solvents. This topic is intended to follow Solutions and Talking solutions and looks at how liquid solvents and different solutes form liquid solutions.

It would also help if you were familiar with the topic From atoms to molecules. In the FAQ section of Talking solutions the following question and answer was put forward:. The rule of thumb is that "like dissolves like".

like dissolves like

For example, water is a polar solvent and it will dissolve salts and other polar molecules, but not non-polar molecules like oil. Petrol is a non-polar solvent and will dissolve oil, but will not mix with water. The rule mentioned above, "like dissolves like", is a very handy way of determining which substances can be dissolved in which solvents.

Types of substances that form solutes and solvents Let's start with a review of the types of substances that can make up solutes and solvents.

Like dissolves like是什麼?

Generally speaking, matter is divided into elements metal and non-metal and compunds ionic salts and molecular. Molecular compounds are further divided into polar and non-polar.

Metals are generally not very soluble in the common solvents but non-metals, molecular compounds and ionic compounds are all soluble in at least one common solvent. Liquid solvents are normally either polar or non-polar but, at high temperatures, liquid salts and metals can act as solvents.

We will limit ourselves to polar or non-polar solvents, marked in red in the above table, as they are the most common solvents.

Dipoles Molecules are made of atoms that have bonded together in set patterns. Depending on how the atoms are arranged in the molecule, the molecule itself can sometimes have different charges on each end of the molecule thus forming a dipole. Such molecules are said to be "polar", while molecules with no or little charge separation are called "non-polar" molecules. Polar molecules are aggressively attracted to other polar molecules, or even free ions, and form strong bonds between themselves.

They feel little attraction to non-polar molecules and tend to ignore them in their rush to find other polar molecules or ions.

Non-polar molecules tend to group together, because they are pushed out of the way by polar molecules, forming weak bonds between themselves. In this way, polar molecules aggressively seek each other out, excluding non-polar molecules from mixing with them and forming a solution. While non-polar molecules form much weaker attractions for each other, they will mix and form solutions.

Like dissolves like! Polar solvents Water is the most common polar solvent on Earth. It will dissolve acids, ionic salts, alcohol, ammonia, sugars and even silicates from rock if under high pressure and temperature. Non-polar solvents The most common non-polar solvents and solutes are the hydrocarbons. Mainly found in crude oils and tars, hydrocarbons, like petrol and mineral turpentine, will dissolve oils, grease, wax, tar, methane gas and most organic molecules.

Like dissolves like Will all solvents dissolve all solutes? Water dissolving salt. Non-polar dissolution. Oil in water. Used with Permission.

If "Like dissolves like" what dissolves gold? Related Topics:. Solutions Talking solutions Colloids, suspensions and emulsions Soap and detergents. Question 1 Question 2 Question 3 Question 4.

How Dry Cleaning Works.There are different ways to incorporate this demonstration in the instructors presentation on solutions. Option A: When hexane is added to a solution of aqueous potassium permanganate, it remains as a clear layer on top of the water solution. When water is added to a solution of iodine in hexane, it remains as a clear layer below the hexane solution. Students should identify the intermolecular forces in the pure substances.

Students should predict whether or not a solution will form prior to mixing the solute in the solvent. After performing the demonstration, students should identify the type of primary intermolecular force of attraction present in the solution the solute-solvent interaction. This demo is usually performed when discussing the formation of solutions involving intermolecular forces and solubility. Predict the relative solubilities of substances. Non-polar solutes such as I 2 do not dissolve in polar solvents like water because the I 2having just London dispersion forces, are unable to compete with the strong attraction that the polar solvent molecules have for each other.

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Thus neither hexane nor iodine dissolves in water. Polar and ionic solutes do not dissolve in non-polar solvents because they have a stronger attraction for each other than for the non-polar solvent molecules. Thus neither water nor potassium permanganate dissolves in hexane. Iodine is a non-polar molecule because the iodine-iodine bond is a pure covalent bond.

London dispersion forces. Water is a polar molecule because the electronegativity difference between the hydrogen and oxygen atoms is medium, 0. The hydrogen bonded to the oxygen atom develops a partial positive charge because the oxygen being more electronegative is pulling electron density away from hydrogen. This partial positive chare is attracted to the partial negative charge on an oxygen atom of a neighboring water molecule.

Water is capable of forming hydrogen bonds between water molecules. Hydrogen bonds are a relative strong intermolecular force of attraction. Potassium permanganate is an ionic compound ion-ion.

Potassium permanganate separates into cations and anions when mixed with a polar solvent, such as water. During the dissolving process water molecules surround the cations and anions using ion-dipole IMFs. Montes, I. Do not try to transport these chemicals in the separatory funnels when you retrieve this demo. They are top-heavy and likely to tip over.

Take a few moments after class to separate the fractions back into their respective flasks. By continuing to view the descriptions of the demonstrations you have agreed to the following disclaimer. The university expressly disclaims all warranties, including the warranties of merchantability, fitness for a particular purpose and non-infringement.