this video is on the strengths of acids and bases we know that an acid wants to donate or does donate a proton and a proton in this case would be an h and we know that a base wants to accept a proton or accept an H from the acid so how do we know how strong these acids or bases are the strength of both of them the acid or the base depends on the extent to which they donate or accept the H to or from water so a strong acid dissociates completely in water so there are six strong acids which I will show you on one of the next couple of slides but full dissociation means that there will be no reverse reaction that will happen here's an example of a full dissociation equation for hydrochloric acid hydrochloric acid is one of the six strong acids so you can see here that this arrow is only going in the forward Direction there is nothing happening in the reverse Direction and what happens our acid here is made up of H's and cl ions it complet completely dissociates into the CL ions and the H is given to the water where we have the h3o plus ion so that is a full dissociation that will happen with these six acids these are the six strong acids you want to remember these so we have nitric acid we have sulfuric acid we have perchloric acid we have hydrochloric acid we have hydr bromic acid and hydro iotic acid the conjugate base column here it's whatever the uh ion is once the acid donates the h so in this case it would be NO3 -1 hso4 -1 C4 -1 CL minus1 BR minus1 and IUS one if an acid has more than 2 H's like sulfuric acid for example that would have two different dissociation steps that go with it this is called a diic acid die because there are two es if you have an acid like phosphoric acid for example that has three that is called a triprotic acid strong bases just like strong acids completely dissociate in solution so instead of creating that hydronium ion like acids you'll have your hydroxide ion and then whatever cat ion was involved with the base originally a lot of your strong bases will come from group one and two on the periodic table strong acids and bases are both strong electrolytes so they will produce conduct electricity here are common strong bases so you'll notice the cat ions for them are from group one and group two and the periodic table so which of the following compounds is a strong acid so this is just a memorized thing the only strong acid there is sulfuric acid H2 so4 so what are these These are called weak acids strong bases we have our calcium hydroxide sodium hydroxide and our barium hydroxide again these would just be weak bases so what is a weak acid and a weak base it has to do with the dissociation so strong acids and bases dissociate completely weak acids and bases um are characterized by little dissociation so they produce few ions and they are weak electrolytes important the re reaction is reversible so you can see in this equation here this double arrow that means the forward reaction is happening at the same rate of as the reverse reaction so these ions they are dissociating over here but then they're unhappy and they're going back to form the original acid and base weak acids and weak bases are weak electrolytes as you may imagine so again just looking at conductivity here a strong electrolyte we have a light bulb fully on a weak electrolyte it is not fully on and then a non-electrolyte anything molecular it would not conduct electricity so your electrolytes come from your ionic substances your non-electrolytes come from your molecular substances there are examples here of weak acids inorganic acids organic but really anything that is not a strong acid is a weak acid so you have six strong acids everything else all the other acids are weak and same thing with bases if it's not a strong base it is a weak base so just a important one that I mentioned in a previous video NH3 it's kind of a hidden base there's no Hydrox oxide ion but you just have to know that that is a weak base again look at your double arrow there for equilibrium so here we're saying if they're strong or weak if you memorize the six strong the rest are weak this shouldn't be too difficult so that is my strong one that's nitric acid hydrochloric acid and then that's acidic vinegar and hydrofluoric something we talked about back in chapter six was leat Leer's principle and this says that the reaction shifts in the direction that counteracts a disturbance so we will get a shift to the right aka the forward reaction if there is a disturbance and this could be from the left side or the right side that the disturbance takes place it could be adding something or removing something and then reverse reaction same thing it could go left depending what we do to the reaction so here it says ammonia we want to write the equilibrium reaction for ammonia and aquous solution so now would be a good time to pause the video and try these three three questions here so here is the equilibrium reaction for ammonia let's concentrate on the top line first so we have our base and it's an aquous solution so there's our water and I'm going to label these guys acid and base my acid wants to give away my H so this H is going here that becomes my conjugate base he becomes my conjugate acid notice the sign changes that occurred and that's the equilibrium reaction make sure you have double arrows there why because NH3 is a weak base so there needs to be double arrows and then below that you can see just the leis structures drawn for all of them the second question says that if additional hydroxide ions are added will it shift left or right so let's look where the hydroxide ions are the hydroxide ions are here so if we add more of them that reaction is going going to want to produce more water and ammonia so this would want to shift to the left if we get more of this we have more reactants to work with it's going to want to shift this way to produce more of these guys another way of thinking about that if we have more of this to balance it we need more of this so we need to produce more of this so we need to shift left to the reverse reaction and the last part C it says if some ammonia molecules are removed from the solution will the reaction shift to the left or right so find ammonia so that's this guy if we are removing that we need to get more of it to replace it so we need to produce more ammonia because we got rid of it so we need to still shift to the left the reverse reaction needs to occur