One thing I can give credit to Khan for is honing in on the aspects of a problem that students will most likely not understand. As that hurdle is passed a light goes on. Understood! The key in learning is being aware of your impediments, and Sal always hits the nail on its head.
This guy's voice reminds me of John Green. These videos help me so much. Not only do I understand these videos much more than my chem lecture class, but the John Green voice keeps me entertained. All the points to Khan Academy.
he didn't. it's essentially dimensional analysis. except, he's explaining and being more explicit writing out everything, to make sure we understand why he's doing what he's doing.
Well done; you're explaining this at the right speed. Ten minutes is excellent. One comment: when multiplying by 100, you might want to remind the students of the effect that has on the decimal point instead of immediately going to the calculator (perhaps you were short on time..). Also - and this is a bit more advanced - before any calculation it might be a good idea to discuss what to expect in terms of the order of magnitude of the answer, as in the calculation at 6:08. Cheers!
There is a way that is so much easier. We want to find mol of 2HCl so n=c(concentration)x v(volume)=0.01875 the molar mad of caco3 =100.09g/mol mass=n(mol) x M(molar mass) =1.877
"The reaction between magnesium with 20 cm³ 2.0 mol dm-³ hydrochloric acid produces 120 cm³ of hydrogen gas at room temperature. What is the mass of magnesium required for this reaction?" help- I don't know how to do the steps to get the answer. I already read & try to understand the example given in our textbook but the example have different unit than what given in the question above and it makes me confuse. (Answer: 0.12g)
you have no idea how much you're affecting my AP Chem grade right now. God Bless you
how are you doing now? did you do well in your exams?
One thing I can give credit to Khan for is honing in on the aspects of a problem that students will most likely not understand. As that hurdle is passed a light goes on. Understood! The key in learning is being aware of your impediments, and Sal always hits the nail on its head.
This guy's voice reminds me of John Green. These videos help me so much. Not only do I understand these videos much more than my chem lecture class, but the John Green voice keeps me entertained. All the points to Khan Academy.
Thank you so much, you have a guaranteed place in heaven.
I honestly haven't found Khan Academy helpful in chemistry. Videos from 2006 are so much faster and explanatory.
YOU MADE MY LIFE SO MUCH BETTER THANK YOU
There's a much easier way to do it, you just made it longer.
he didn't. it's essentially dimensional analysis. except, he's explaining and being more explicit writing out everything, to make sure we understand why he's doing what he's doing.
Chemistry Final Tomorrow - Thanks for the Help!! : )
And verily, it is written I went to explore each field of new knowledge and Sal Khan was there shining his light!
I understand you want to break it down to the simplest but you should also do the much faster way lol
Regardless good video!
What’s the faster way?
Well done; you're explaining this at the right speed. Ten minutes is excellent.
One comment: when multiplying by 100, you might want to remind the students of the effect that has on the decimal point instead of immediately going to the calculator (perhaps you were short on time..). Also - and this is a bit more advanced - before any calculation it might be a good idea to discuss what to expect in terms of the order of magnitude of the answer, as in the calculation at 6:08.
Cheers!
i agree! the decimal notations are important.
Thank you. It's very nicely explained.
احسن حاجة الترجمة دي بتفدنا جدا استمرو
Thank you so much, you saved my soul
OH MY GOD !!! Thank you sooooooooo much
This is a much better explanation than the one given by my teacher
thx :)))))))
Easier: 25 ml HCL x (0.750 mol HCL / 1000 ml) x (1 mol CaCO3 / 2 mol HCL) x (100g CaCO3 / 1 mol CaCO3) = 0.937 g CaCO3
The way my teacher explains it is GMRU. Grams, moles, (mole) ratios, units. It makes sense to me anyways.
There is a way that is so much easier. We want to find mol of 2HCl so n=c(concentration)x v(volume)=0.01875 the molar mad of caco3 =100.09g/mol mass=n(mol) x M(molar mass) =1.877
very helpful. Thank you!
great job, i really need help in chemistry
Finals on monday!! :(
im dead!!
how did you do?
Is why I like this guy he help m always!
The game is of my concentration my friend!!!!! You like these that's why you concentrate more hence more understanding :D
great video, thanks
thanks for the help bro
if u use the formula and substitute the values..it would be much easier to understand..
Confusing
thank you thank you thank you!!!!
Thank you.
Hey SophieGlovs1D he is using a digital black board and a pen to write all of his answers
i dont like the way he does his dimensional analysis
me neither lol
"The reaction between magnesium with 20 cm³ 2.0 mol dm-³ hydrochloric acid produces 120 cm³ of hydrogen gas at room temperature. What is the mass of magnesium required for this reaction?"
help- I don't know how to do the steps to get the answer. I already read & try to understand the example given in our textbook but the example have different unit than what given in the question above and it makes me confuse.
(Answer: 0.12g)
@khanacademy aren't we are suppose to multiply no. of moles of HCl by 2? i.e. 0.0187x2 as the derived answer was for single HCl and we had 2HCL?
Is there a precipitation reaction example?
Brah u sooooooo good thx!!
npp
you should be teaching at ucla.....
Maybe use the formulas next time? N=C•V and N=M/MM it would make it faster and easier to understand
awesome!!!!!!!!!!!!!!!!!!
Only if Khan was my chemistry teacher...
tomorrow im going to wake up and forget all of this useful information :(
Aren't there only supposed to be two significant digits, and not three? (0.94g, not 0.938g)
Countries use different Sig digs. In Canada we wouldn't count the 0.
I was confused with that too!
thankkksss you rock :)
Practice!
this video and the setup of his problem is very confusing for us students that chemistry does not come naturally to. to spread out...do step by step.
In India we do it in 1 min without calculators.
The first part of your dimensional analysis is confusing
Never mind
I got 0.945
uwu