Chemistry quiz 2: win up to 6 steem! :)
It's time for the next round of my little chemistry quiz. What could be more fun than activating your brain and at the same time having the opportunity to win up to 6 steem. :-)
Rules - what are the requirements to win the prize?
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You have to upvote this article with at least 20 % of your voting power (no 1 % votes please :).
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Winner is the person who is the first one to post the correct solution (correct number and correct unit). The prize for the correct answer are 5 steem. I will send it to the winner immediately after I received the rewards for this article.
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If the winner had also resteemed my article, he will receive one additional steem (altogether (5 + 1) steem = 6 steem).
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If nobody finds the solution until Friday, April 21th, 2017 at 10 pm (German time!) the prize (5 steem) will be added to the next competition.
Nitrogen in a discharge tube:
Von Alchemist-hp (talk) (www.pse-mendelejew.de) - Eigenes Werk, FAL, https://commons.wikimedia.org/w/index.php?curid=10942390
Challenge to solve:
Assuming that in the room air of the still empty bedroom of a new build house there are exactly 7.79215 ∙ 1026 N2 molecules. The floor area of the room is quadratic with an edge length of l = 4.00 m.
Given as help:
- The mass percentage of N2 in the air amounts to 75.518 %.
- One single N atom has a mass of 14.007 u.
- 1 g = 6.022 ∙ 1023 u.
- The density of the room air is assumed to be ρ = 1.2 kg/m3.
Question:
What is the height of the bedroom (from the floor to the ceiling) in m?
Calculations are required. :)
2.5 m
There's 7.79215x10^26 N2 molecules. A single molecule = 14.007u. So you work out the total mass contained within the subset of consideration: (total number of N2 molecules ) x (2 x weight of single N molecule). Then consider the density of the subset of the mass rho = 0.75518 x 1.2. Then density = mass/ volume => height = mass/(16x1.2x0.75518)
Congrats, that's the correct solution!
You are the winner of this round.
That was really creative to calculate the heigth of the room by the number of N2 molecules in it!
Congrats . Now, i know where I'm off.
Excellent work
I used to like Maths and not so much a Chem person but this looks more like a Maths problem so I decided to have some fun with this.
N2 percent in air： 75.518%
N2 mass 14.007 u
1g = 6.022 x 10^23 u
Air density: 1.2kg/m3
N2 presence = 7.79215 x 10^26 molecules
Room area in meter square = 4 x 4 = 16
Height of room in meter = H
Volume of air in room = 16 x H
Mass of air in room in kg = 16 x H x 1.2
Mass of N2 in room in g = 75.518% * 16 * H * 1.2 * 1000
Mass of N2 present in g = （7.79215 * 10^26 * 14.007 ）/ (6.022 * 10^23 )
Solving for H...
Mass of N2 in room in g = Mass of N2 present in g
75.518% * 16 * H * 1.2 * 1000 = （7.79215 * 10^26 * 14.007 ）/ (6.022 * 10^23 )
Therefore Height of room in meters (H) = 1.25m
By logic the height seems low. Maybe, I went wrong somewhere if I'm wrong but perhaps give some clue to the next guy. :-)
You are very close ... Read carefully again how I exactly formulated "Given as help" ...
(I will be offline for quite a while now, just in case you wonder, if I don't reply immediately to your next try - good luck! :)
Sorry, I have to give up. I think its the quadratic thing that I don't get.
@ace , the only mistake which you made was that you used the mass of a single N atom instead of the mass of N2.
I feel a little bit sorry that you didn't win the prize because you were the first one with a nearly correct solution. At least I upvoted all your comments with 100 % as compensation. :-)
Understood. I'm off because of N2. All for the fun anyway so it's ok. That why i have the details so someone could figure out the right answer and enlighten me. So, my maths is still good . My chem still no good. :-)
Thanks. I think I took into account of those.
Will relook a bit.
Congrats again, @diracdnb , your prize has just been sent! :)
'vote-buying' is frowned upon on Steemit.
Other than that: nice idea for a quiz.
I recommend to call it the #chemistrychallenge for better results.
... and @felixxx frowns because of 'vote-buying'.
My point of view: I invest quite some time in these quizzes and give the participants a chance to gain a few steem. The ones who decide to take part and upvote me don't lose anything by doing that. Everybody decides himself if he likes the conditions and thus want to take part or not.
Of course I want to make profit with my articles and also with my quizzes in the long run, but at the same time I honestly try to offer interesting self-made (all quizzes, chemistry, chess or whatever else are invented by myself) content. I am still not sure if I will continue this 'series' - it depends on if enough members like it and take part. If a quiz is solved too early like last time I offered it, then it is not profitable at all. However if it is too difficult it may be boring for most readers as well, so it's not an easy task to find the right 'balance'.
By the way when I was new here I offered similar quizzes without the chance to win a prize. The result was that not many people took part (another reason can be of course that I didn't have many followers these days). Just as an example @twinner wrote as feedback in the German chat channel, why should people risk to give "stupid" answers even if they have nothing to win?
And yes, true, I don't like 1-%-bot-votes.
It's no problem though that you don't like the way this competition is presented. Different people, different opinions. And thanks a lot for your suggestion for a better title!
I'm saying this, because posts have been flagged for vote-buying.
Thanks for information.
Actually I chose the conditions just similar as I saw it elsewhere. You are right, the only difference from other challenges is that the winner has to upvote with at least 20 % of his voting power (I myself normally vote with 50 or 100 % anyway if I like a post).
I like this, and I hope someone will give you an answer. I will stay out of it though :)
Nice that you give someone else the chance to win the price. :-)
What do you think about the level of these quizzes so far? Is it appropriate in your eyes (of course I know that's subjective, and different persons may have different opinions)? If I make it too difficult I fear most readers won't stay interested ... but too easy questions would be boring as well ...
If people are having fun and giving them a go then they are sufficiently difficult and entertaining enough to try. I think they are fine, you make people do a little bit of work :)
It's a fun idea IMO. So long as your participation remains good then I think you should keep it up!
Good to hear your opinion, my friend. :)
I'm always excited for things that try to engage the community and get people thinking. :D
Nice and interesting quiz! It's unfortunate that I don't know much about chemistry! ;)
Hm ... you may try to solve it together with some friends? :-)
Thanks for cheering me......but I think I shouldn't even try it! :p
Have you ever seen a winner who didn't try to win? :-)
(Just kidding, of course you decide yourself if you want to give it a try or not. :)
I understand what you mean.... I did not study chemistry a long time ago! That's why I'm not good at chemistry at all! Thanks again for your nice comment. ;)