In this video you're going to discover more about strong and weak acids
And what makes them this way?
The word acid comes from the Latin word a ser meaning sour and you may have eaten some of them today
lemons Contain Citric acid and makes the Flavor of others seem less acidic tea contains tannic acid vinegar
Ethanoic or acetic acid and Fizzy drinks carbonic acid
In contrast strong acids are often used in school science labs for experimentation
But they have important uses in industry and the everyday world [sulfuric] acid for example is found in car batteries
But industry uses 200 million tons annually for the chemical industry
hydrochloric acid found in your stomach and nitric acid are also examples of strong acids
We have established in our video
What makes something acidic [that] acids react with water to Produce hydrogen ions or more strictly speaking?
Hydroxo Nia my arms
strong acids like the three mentioned above
Dissociate 100 percent into their ions like this
Most acids are weak and remain largely as molecules in solution ie they do not ionize very much note
The equilibrium arrow here
As its can be identified by using full range indicator from naught [to] [seven] on the Ph scale
Ph is a measure of the concentration of hydrogen ions for example at Ph [zero]
There is one mole of hydrogen ions per liter
At Ph [1] just [1/10] of a mole of hydrogen ions per liter
Each increase of one unit of Ph is a Tenfold
reduction in Hydrogen Ion [concentration]
So [when] you reach ph 7 there are only 10 to the power negative 7 or
Zero point zero zero zero zero zero zero one mole of hydrogen ions per liter
Here there are also an equal [number] of hydroxyl ions, and we have arrived at pure neutral water
If you dissolve one mole [of] a strong acid [like] HCL in water to make one liter of solution it dissociates completely
into ions
So you also get one mole per [liter] of hydrogen ions and a ph of zero to get a solution of for example?
ph, [four] you need to dilute this with
10,000 times its volume of water. We still have a strong acid, but it is very dilute
however, if you dissolve one mole [of] a weak acid like ethanoic acid also called acetic acid to make one liter of solution
It remains mostly undissociated
Molecules, that's why it smells the molecules can easily move into the air
Let's say the acid is only
0.01 percent
Dissociated so only one molecule in [ten] [thousand] are split into ions
Although the concentration of the acid [is] 1 mole per [liter] the concentration of hydrogen ions is only
0.0001 moles per liter that is 10 to the power negative for
Making the Ph 4 so here is an example of a fairly
Concentrated acid which is weak
Here are two common weak acids vinegar and carbonic acid
Vinegar is also known as acetic acid or ethanoic acid
Ethanoic acid reacts with water to produce [Hydroxo] [neem] ions and Ethanoate ions
strong acids however are totally dissociated into their ions which is indicated by the non reversible arrow in the example shown for
hydrochloric acid and water
Little test to summarize here are the four pictures that you saw earlier of some acids dissolved in water can you say which to show?
concentrated solutions and which to show dilute solutions and
Can you say which to represent a strong acid and which to represent a weak acid pause and think?
The answer a is both concentrated and fully dissociated so strong
B is also concentrated, but not fully dissociated so weak
C is Dilute but strong because it is fully dissociated and D is dilute and weak?
Most acids are commonly occurring organic acids such as you find in lemons or vinegar
Which are all weak so remain mostly as molecules and often have a smell there are only a few
strong acids mostly non metal oxides dissolved in water like sulfuric and nitric acids
But there's also hydrochloric acid found in your stomach to aid digestion