Key Properties and Uses of Acids and Bases Explained

Some properties of acids. Acids have sour taste. For example, in this lemon, it is sour because it has an acid called

citric acid and also vinegar. Vinegar have acidic acid. Most sour foods, even sour candies have some acids, but they

are weak acids. In foods, we do not have strong acid. Another property of acid is they react with metals. Not all metals,

many metals. That's why in car batteries you might have seen this corrosion because batteries have sulfuric acid and

sulfuric acid reacts with metal and it corrods. Here another example of using acid to dissolve metal. I think in a

movie or somewhere they use acid to break out of the gel but not all of the acid silver gold platinum these and some

other metals do not react with acids. And another property is there's something called litmos papers. We use

litmos papers to check the acidity or basicity. There are two types of litmos papers. Blue Litmas paper and red litmos

paper. Blue becomes red when there's an acid. Just remember B. Blue becomes red when there is an acid. So opposite is

red litmus. You will see in a minute. Red litmus become blue when there's a base. If you remember one thing, it's

easy to remember the other one. So these are some of the common acids we use. Uses I don't want you to remember, but

it's good to remember because they are everyday chemicals. What I want you to remember is these three acids nitric

sulfuric and HCl and also I want you to know that they are strong acids and also I want to remember acetic acid is a weak

acid that's acid in vinegar and these acids we don't use it very often but of course there are uses acid is a good

acid to remember we consider it as a moderately strong probably HCL is the most used example in our class and in

our labs and this is the acid actually in our stomach this is sulf sulfuric acid and this is the mostly produced

chemical in USA. You can see H2SO4 there are two hydrogen atoms here and you can see this whole molecule is a

covealent molecule. It is not ionic but we know that in aquous medium it can release H+. There are two hydrogen's

connected to this oxygen and these are ionizable hydrogen. They can ionize in water. There are two of them. But in

nitric there's only one ionizable hydrogen. Therefore in water it will give only one hydrogen ion. Acidic acid

is different because this is a weak acid. And also if you see this hydrogen also connected to oxygen. There's a

group in most of the weak acids called CO caroxyic group. We call these acids as caroxilic acids. So acidic is one of

the caroxilic acid. Formic acid. This is another caroxilic acid. Now the bases some characteristics of bases. They are

slippery. There are many bases we use including soap as cleaning agents. And if you ever taste it, it's not sour. It

has bitter taste. And we can use litmus papers to identify bases. In this case, red becomes blue in bases. And most of

the bases have hydroxide ions in water. So these are the common bases. I want you to remember these three. Sodium

hydroxide, potassium hydroxide and calcium hydroxide. I want you to know that they are strong because they are

fully ionized in water. So ammonium hydroxide is aquous ammonia and also these are weak bases except this sodium

bicarbonate or sodium hydrogen carbonate the same thing except that all other bases we see here have O just like acids

have hydrogens generally bases have hydroxide ions you can see that magnesium hydroxide sodium bicarbonate

some of the uses are anti- acid probably you might have seen in the store anti- acid tablets Because sometimes you might

have problems with acidity in your stomach. So if you use these ant acids, these bases can react with acid in the

stomach, hyaluronic acid in the stomach and it can neutralize it. You will not feel the pain of that acid. But we

cannot use anti- acids just to cure the disease. The reason you have more acid in the stomach is some other disease.

That disease is not going to be cured by these chemicals. Therefore, it is very bad to use antiac acid over and over to

relieve your pain. We need to find the exact reason for that. I just told you to discourage taking anti- acid in a

consistent basis. Strong acids and strong bases are completely ionized in water. But weak acids are weak bases do

not. They are partially ionized in water. Most of the molecules of weak acids are weak bases are present as

molecules in water, not as ions. That's why they are called fake acids and bases. Sodium hydroxide in water, it

dissociates into sodium plus and O minus ions. So this is fully dissociate. All sodium hydroxide dissociate into sodium

and hydroxide ions. There are no sodium hydroxide formula units in water. Everything is dissociated. Same with

hydrochloric acid HCl. When you put in water, we do not see any HCl molecules. We see only H+ and Cl minus ions. Those

are strong acids and strong bases. But for weak acids or weak bases, let's say ammonium hydroxide or ammonia in water,

they give ammonium plus an hydroxide ion. But this is not fully dissociated. This is partially dissociated. That

means you have both ammonium ion and hydroxide ion and also you have ammonium hydroxide. So the meaning of weak is it

is not fully dissociated. That's what this double arrow means.