Sciencemadness Discussion Board - Grade 10 Highschool Science

Grade 10 Highschool Science

Chemorg42 - 28-5-2020 at 12:04

:mad:

https://www.youtube.com/watch?v=g-biRwAVTV8
IT HURTS!, It hurts so much!

Fulmen - 28-5-2020 at 12:53

Could you perhaps explain exactly what the video claims, and why it "hurts"? Last time I checked this isn't the f'ing youtube commentary section.

Sigmatropic - 28-5-2020 at 13:12

Oversimplification at its finest. It's the equivalence of quantification to the point of failed utility. Yes, it is chemistry, yes it is, at least somewhere, correct. but it does not serve any purpose whatsoever.

mackolol - 28-5-2020 at 13:15

Maybe if someone is not good at chemistry in highschool and it isn't his main subject it is easier to remember for him this way... I don't see any purpose in this topic.

[Edited on 28-5-2020 by mackolol]

j_sum1 - 28-5-2020 at 20:25

It wasn't dreadful. But it was really little more than the animation of a dictionary definition. I doubt anyone would be able to sensibly extrapolate from the generalisaton given to any specific examples. The presenter certainly couldn't: for the double displacement reaction both products were soluble and so it is a stretch to say that the reaction had actually occurred.

For the sake of a 14 year old who needs to somehow regurgitate some isolated information to "pass" (for some reason... Why do we do this in our education system?) then maybe it is alright.
To illustrate a bit of terminology that somehow a student had become fuzzy on and thereby equip them to progress, again ok at least in the hands of a competent teacher.
As a scientific explanation... It's a bit like calling the three little pigs literature: formative, maybe. Illustrative, perhaps. Meaningful, Nup!

Chemorg42 - 29-5-2020 at 09:05

Exactly, j_sum1. For me, it was doubly tragic because of the school system's pathetic attempt at relevance to today's youth. A 90s sitcom, really?

j_sum1 - 29-5-2020 at 14:35

A 1960s sitcom.

Chemorg42 - 30-5-2020 at 09:57

1960s?
My bad, never seen, nor do I care to.

DraconicAcid - 30-5-2020 at 11:02

Ouch. You're right, that was painful. Even ignoring the references to the 1960s, and the slow monotonous worse-than-Kirk manner of speaking........
They decided that magnesium chloride was Mg(Cl)2 and that copper nitrate was CuNO3.

Ubya - 31-5-2020 at 01:46

ignoring the wrong chemical formulas and the cringy aspect of using the fintstones, i can see why he did it. i gave private chemistry lesson to a guy a few times, he is honestly dumb as a rock, i really had to use my imagination to explain to him some basic chemistry concepts in a form understandable by him. the dumber the kid, the crazier the example.

[Edited on 31-5-2020 by Ubya]

Chemorg42 - 31-5-2020 at 12:26

@DraconicAcid, you're right, the speaker sounds like he's decoding a stack of punchcards. My guess is that this video was produced in some content mill, and even the speaker new how cringy it was.
Also, in the same lesson, I was told that an acid is "A covalent compound that donates hydrogen ions when placed in water", and (even worse) "A base is an ionic compound which donates hydroxide ions when placed in water."

DraconicAcid - 31-5-2020 at 12:38

Quote: Originally posted by Chemorg42

@DraconicAcid, you're right, the speaker sounds like he's decoding a stack of punchcards. My guess is that this video was produced in some content mill, and even the speaker new how cringy it was.
Also, in the same lesson, I was told that an acid is "A covalent compound that donates hydrogen ions when placed in water", and (even worse) "A base is an ionic compound which donates hydroxide ions when placed in water."

Well, that's the Arrhenius definition, which grade 10 insists is the only definition. I have to break my first-year students of the habit of saying that "and acid and a base react to give a salt and a water", ignoring the possibility of ammonia or carbonate acting as a base. Are insisting that aqueous ammonia is actually "ammonium hydroxide" (and it's the hydroxide that acts as a base).

Chemorg42 - 31-5-2020 at 13:12

I know that this is the standard grade 10 definition, but as someone who educated myself about Lewis acids and bases over lunch during grade 9 science, it is still quite painful.

j_sum1 - 31-5-2020 at 14:33

Quote: Originally posted by Chemorg42

I know that this is the standard grade 10 definition, but as someone who educated myself about Lewis acids and bases over lunch during grade 9 science, it is still quite painful.

Good for you.

In defense of Arrhenius theory, I think it provides a practical foundation. It makes a difference when students see Ca(OH)2 and immediately recognise it as basic.
Most high school syllabuses limit to aqueous solutions for acid-base work and so the simplistic classification of, "acids have H+ and bases have OH- in solution" is practical and accurate enough. A proper understanding of bronsted-lowry theory requires a foundation of equilibrium which is outside the scope of middle school curricula. I have no bones about students operating under Arrhenius theory and then blowing it out of the water with substances like NH3 and FeCl3. That is what happened historically.

Lewis theory is really not necessary until students start learning organic chemistry and reaction mechanisms.
The fact that the theories build on one another sequentially rather than contradict one another helps to lead students incrementally to a place of conceptual understanding.

DraconicAcid - 31-5-2020 at 16:43

Arrhenius is better than nothing, but Bronsted-Lowry is far more useful, until we get to the point where we actually need Lewis.

Chemorg42 - 31-5-2020 at 17:04

@j_sum1, I agree with everything you said, except for one thing. You said that lewis acids and bases are not required until organic chemistry and reaction mechanisms. Perhaps they are not strictly "Required" until then, but the reason I originally sought to understand them was so I could understand how solutions of metal salts could be acidic.

Chemorg42 - 31-5-2020 at 17:06

Also, the part that really annoyed me about the lesson was where it stated that acids are "Covalent compounds" and bases are "Ionic compounds." Does anyone know where this particular idea comes from?

DraconicAcid - 31-5-2020 at 17:39

Quote: Originally posted by Chemorg42

Also, the part that really annoyed me about the lesson was where it stated that acids are "Covalent compounds" and bases are "Ionic compounds." Does anyone know where this particular idea comes from?

Acids are covalent- H+ is too small to exist as an ion without a bond. If you accept Arrhenius's idea that only hydroxides are bases, then bases are ionic hydroxides or ionic oxides (I used to work with a guy who insisted on calling ionic oxides "basic anhydrides"- they weren't really bases because they weren't hydroxides).

Chemorg42 - 31-5-2020 at 17:42

Oh, that makes sense, thanks.

wg48temp9 - 2-6-2020 at 01:52

A snip from the video:

I find it hard to believe that normal (undamaged brains) children after 9+ years of education are taught chemistry that way. Just a year or two before they go to university !!!