Solubility Rules: Explanation & Practice

The solubility rules are important for quickly figuring out is a substance is soluble or insoluble in water. Often students are required to memorize the rules for solubility shown below:
-----
Top rules supersede any lower rules.
In general, salts of:
* Group I elements (Li+, Na+, K+, Cs+, Rb+) are soluble.
* NH4+ are soluble.
* the nitrate ion (NO3-) are generally soluble.
* of Cl-, Br-, and I- are soluble. Exceptions Ag+, Pb2+, and (Hg2)2+
* most sulfates are soluble. Exceptions: Ba2+, Ca2+, Pb2+, Ag+, Sr2+ .
*most hydroxide salts are only slightly soluble. Exceptions: NH4+, Li+, Na+, K+
---
In this video we’ll introduce and practice these rules, building your memory as we go. Then we add several other rules that you’ll see from time to time.
Check with your instructor to see which solubility rules you need to memorize. Some teachers allow you to use a solubility chart but you may still want to have the most common rules memorized.
Note that all compounds are soluble to some degree. If that is a very small amount, we say they are insoluble.
Also note, that when we discuss solubility, remember that solubility is affected by temperature, generally becoming more soluble as the temperature increases.

[@krishnaswamy6684]

You explain so well and methodically. I hope students will find these videos. This teacher is awesome!

[@wbreslyn]

Thanks for the kind words! --- Dr. B

[@rahmahdalhat8484]

It is astonishing how underrated this video...thank you for an amazing effort. Will continue to watch your other videos

[@pantone448c0]

Tysm for this great video! My chem teacher just told us that we had to memorize the halide and sulfide exceptions the day before the test 😅 Ong you’re a lifesaver 😁

[@aayandadan9340]

i was freaking out an hour before my test and you helped me a lot, thanks !

[@ninamurgolo632]

I wish I found these tutorials much sooner in the semester. However, I did benefit by studying for my final as a review. They are clear and to the point, very easy to follow and understand. Thank you

[@wbreslyn]

Glad it was helpful!

[@AK-op4be]

THANK YOU. you made this so much easier to understand 😭😭😭 ive been struggling with it for the longest.

[@rodolphebourdet959]

Bonjour, honestly, gorgeous! as french senior I re-start the sciences from the beginning and your videos are so helpful. I do practise both language and siences at the same time. intense but efficient! a big cheer for you. I pray for you :-) Rodolphe

[@wbreslyn]

That is efficient! You get to practice language skills and chem. Very nice!

[@rodolphebourdet959]

@@wbreslyn Dear Wayne, a reliable summarize from you. Clever and delicious! I offer you a great deal of positive thoughts for this wonderful day. 🧘🏿‍♂️💫 Rodolphe

[@mariaarellano8563]

Thank you Dr. B. What an awesome video :)

[@antisymmetric237]

I love it. Great job on explaining the steps for solubity.

[@hassanbaksh5279]

Sir, At 7:27 you were saying exceptions are NH4+, Li+, Na+ and K+ but after that you said they will be (aq)

[@wbreslyn]

Hmmmm. Group 1 elements (Li, Na, K) and NH4+ are almost always soluble. So compounds with these should be soluble according to the solubility rules.

[@hassanbaksh5279]

@@wbreslyn Thanks sir

[@sanjaygore2107]

Respected sir Nice .

[@jaredguerra9324]

Can you please look up "Table 4.1 Solubility Guidelines for Common Ionic Compounds in Water" and explain why the diffference in solubility for CaSO4, AgSO4, and Ca(OH)2. I saw the solubility table showed slightly soluble for the first 2 and the last one is a strong base of group 2A metal hydroxides. I just need closure on the matter of why not soluble?

[@activeman464]

شرح ممتاز Perfect teacher

[@wbreslyn]

Thanks!

[@ericaoberoi1301]

Saving lives out here

[@kaholeung9443]

very useful , thank you

[@crawfordm1589]

GREAT VIDEO!!

[@orangecaprinun]

thank you thank you thank you!

[@ChastherYanda]

Thanks Dr B you really help me with your explanation😊

[@wbreslyn]

Excellent!

[@zoyasayyyed.2]

Thank you so much sir ❤️ Because of you I can score good marks in my chemistry exams ❤️😭 thank youu ❤️ a warm thank you ❤️🥰

[@ANIKETRAJ-w6i]

Good sir

[@curtpiazza1688]

Great lesson!

[@SS-rb5ys]

you are a great teacher, I understand everything and the solubility rules thanks to you! your teaching makes everything easy and understandable! Thank you

[@wbreslyn]

Thanks for the kind words!

[@electro_yellow9295]

Wait how is PbI2 not soluble but in the rules it it says that I- is soluble and PbI2 has an iodide in it?

[@wbreslyn]

PbI2 is one of those exceptions. If you see Pb or Ag be careful! Check the rules in the video. You'll see it Pb there.

[@antisymmetric237]

Thank you.

[@maxarnd]

Gran video! Saludos de Perú xdd

[@wbreslyn]

Thanks!

[@susmitamondal4824]

Sir, Can you please explain Why Francium(Fr) is not included in the first statement?

[@wbreslyn]

It is radioactive and doesn't stay around for very long.

[@victoriaogedegbe4931]

So some rules says “all metals” but what if some had non metals in it. Like rule 3. If nitrate had a non metal with it, is it soluble?

[@wbreslyn]

I would suppose so. NH4NO3 certainly would be. But since the nitrate ion has a 1- ionic charge it doesn't bond with non-metal ions which are negative.

[@tristango1685]

Why is NaOH soluble? Isn’t hydroxide an exception when it comes to solubility?

[@wbreslyn]

Group 1 elements, like Li, Na, K hydroxides are soluble. Sort of an exception.

[@ruthbeisheim8299]

Is your solubility table that you reference in your videos available for download?

[@wbreslyn]

Here is the full version of the table I use: en.wikipedia.org/wiki/Solubility_chart

[@henripavot4492]

But why ARe the solubles solubles ? This is what would be interesting to know. Can you explain ? Thank you.

[@mikeboyd1961]

Group 1 always soluble because their charge is only 1+. Once you get 2+, 3+ and greater the solubility decreases. More charge means stronger ionic bonding and lower solubility. Similarly for the anions. Halides generally soluble as 1-. CO3 2- & PO4 3- generally insoluble except when with monovalent cations ie group 1 and the ammonium ion. NOW you are going to ask what about OH- ion which seems to be an exception. I think this is partially down to charge to mass ratio but am guessing a little. Mol wt OH- is 17. Cl- 35.5, CO3 2- 60, PO4 3- 95. I am fairly sure that there will be other effects as well. Quantum effects and Nuclear Resonance Effects maybe? We need more help from the experts!

[@bunny4173]

DR B . thanks for the video .anyway is there any explanation as to why these salts are insoluble ? like AgCl etc

[@wbreslyn]

That is really the important question! There is a good discussion at www.reddit.com/r/askscience/comments/3mjewb/why_are_some_salts_insoluble/ It's not an easy question to briefly answer.

[@devaiahkodira8596]

Sir give examples of which elements are solid, liquid,gas and aq.

[@yasyasmarangoz3577]

Do you need any help?

[@devaiahkodira8596]

@@yasyasmarangoz3577 s plz

[@yasyasmarangoz3577]

@@devaiahkodira8596 Ok ROOMTEMPERATURE: Fe(s) H2O(l) H(g) NaCl in Water is NaCl(aq)

[@devaiahkodira8596]

@@yasyasmarangoz3577 wow thank you it helps a lot

[@yasyasmarangoz3577]

@@devaiahkodira8596 Your welcome, it makes me happy to know that I've helped someone👍

[@leighannesantos3334]

where's the link for the practice? and thank you for this vid!

[@wbreslyn]

Happy to help! In this case it's embedded in the video (that's why is longer than my usual videos). You can probably find many other videos I made by searching on "is _______ soluble or insoluble". For example "is CaSO4 soluble or insoluble".

[@MigzAztig21]

is aluminum trichloride solube in water?

[@wbreslyn]

Oh yeah. solubility in water 439 g/L (0 °C) 449 g/L (10 °C) 458 g/L (20 °C) 466 g/L (30 °C) 473 g/L (40 °C) 481 g/L (60 °C) 486 g/L (80 °C) 490 g/L (100 °C) en.wikipedia.org/wiki/Aluminium_chloride

[@huzaifaabedeen7119]

What are the prerequisites for this video??

[@bunny4173]

Famialiarity with general chemistry ... U can find many good books on gen chem ... Like chemistry the central science

[@shivamsikotra3733]

very good video

[@wbreslyn]

Thanks!

[@hamzabaig8856]

If only you were my chemistry teacher .... You're one of a kind. 🥸😄

[@hamzabaig8856]

TY!

[@ARGAMING-vz2jc]

I AM FROM BANGLADESH🇧🇩

[@wbreslyn]

Awesome!

[@ranamuruodedara183]

Good👍👍

[@wbreslyn]

Thanks!

[@huzaifaabedeen7119]

Where is the link to practice videos sir??

[@wbreslyn]

That is a good question! I don't think I ever made that video (I'll put it on my list). But this video might be of help: kzbin.info/www/bejne/qZ_boJidr7uhjdk

[@huzaifaabedeen7119]

@@wbreslyn thank you Dr. B for your reply. Are the solubility rules applicable for water only or for any solvent?

[@wbreslyn]

@@huzaifaabedeen7119 Good question! They apply to water only.

[@shanimap2721]

Thank u sir

[@wbreslyn]

Welcome!

[@EcoTravelDiscoveries]

I didn't understand why did you say that calcium hydroxide is insoluble? (7:34)

[@wbreslyn]

Ca(OH)2 is relatively insoluble in water, sometimes listed as slightly soluble. All compounds will dissolve at least a small amount but if it is very small we call it insoluble. --- Dr. B (see en.wikipedia.org/wiki/Calcium_hydroxide)

[@pi4313]

my chart looks different than yours

[@dreclawwoo9615]

Then a duel must be set to decided which one has the true chart in the old roman ways, when and where is the only question you need to ask. FOR ONLY 9.99!!! (i am losing braincells)

[@pi4313]

@@dreclawwoo9615 lol

[@ZUCULENTOZOPRO]

thanks sir

[@wbreslyn]

Most welcome!

[@ANIKETRAJ-w6i]

Ma ka