Atenção! Esta questão foi postada ha mais de 30 dias!
Exercício de grandezas quimicas
Exercício:
a analise da vitamina B12 mostra que ela é constituida de 4,34% de colbato, quantos atomos de cobalto existem em 1,5 g de vitamina b12 ?
a analise da vitamina B12 mostra que ela é constituida de 4,34% de colbato, quantos atomos de cobalto existem em 1,5 g de vitamina b12 ?
Bom Fernanda.. Sem saber a fórmula da Vitamina B12, é IMPOSSÍVEL responder sua pergunta..
Estou aqui pra ajudar, mas ajude também com exercícios corretos, vai ?!
Obrigado.
Ah.. Se vc fornecer tbm a massa molar da vitamina e a massa molar do cobalto, dá pra fazer seu exercício. Ao menos algum desses dado o exercício deve dar, e não é atoa.
Valeu
OI, olha dá para resolver o exercício sim !!!!!
O que falaram antes é verdade apenas para facilitar você descobrir como se faz, porém ai tem dados que não levaram em conta.
Você tem o valor da massa total que é 1,5g de vitamina B12, e o cobalto tem 4,34% da massa dessa vitamina. Assim 4,34% de 1,5g é 0,0651g de cobalto, ou ainda em notação científica que facilitará as contas você terá 6,51×10-2 g.
Bom, agora que já sabemos quanto em massa há de cobalto na amostra de vitamina B12, temos de saber quantos átomos de cobalto há nessa amostra. Sabemos que um mol de algum elemento equivale a 6,02×1023 átomos e um mol de cobalto equivale a 58,9332g. Com isto agora é fácil desenvolver a conta e chegar no resposta esperada. Como são diretamente proporcionais, é só aplicar a famosa regra de três.
Assim temos:
58.9332g ——————— 6,02×1023 átomos
6,51×10-2 ——————— x átomos
Multiplicando em cruz:
58,9332.x = (6,02×1023).(6,51×10-2)
58,9332.x = 3,91902×1022
x = 6,64993586×1020 átomos
Portanto aproximadamente 6,65×1020 átomos de cobalto em 1,5g de vitamina B12.
(técnico em química)
Parabéns Lucas, matou à pau.
E André, veja se pensa um pouco mais simples da próxima vez… NÓ CEGO
Hey there! I’m at work browsing your blog from my new apple iphone!
Just wanted to say I love reading your blog and look forward to all your posts!
Keep up the outstanding work!
Heya! I know this is somewhat off-topic but I had to ask. Does managing a well-established
website such as yours take a large amount of work?
I’m completely new to operating a blog however I do write in my journal on a
daily basis. I’d like to start a blog so I will
be able to share my personal experience and thoughts online.
Please let me know if you have any recommendations or tips
for new aspiring blog owners. Thankyou!
Fantastic goods from you, man. I’ve understand your stuff
previous to and you’re just extremely excellent. I actually like what you’ve acquired here, certainly like what you are stating and the way in which you say it.
You make it enjoyable and you still take care of to keep it smart.
I can’t wait to read far more from you. This is really a tremendous site.
No matter if some one searches for his necessary thing,
so he/she wishes to be available that in detail, thus that
thing is maintained over here.
Hello! This is my first comment here so I just
wanted to give a quick shout out and say I truly enjoy reading your articles.
Can you suggest any other blogs/websites/forums that deal with the same
subjects? Many thanks!
It’s actually a cool and helpful piece of info. I am
satisfied that you simply shared this helpful info with
us. Please keep us up to date like this. Thanks
for sharing.
Thanks for sharing your thoughts. I truly appreciate your efforts and I am waiting for
your further post thanks once again.
It’s very easy to find out any topic on web as compared to textbooks, as I found
this paragraph at this web page.
Saved as a favorite, I love your website!
Thank you, I’ve recently been searching for info about this topic for a
while and yours is the greatest I’ve came upon so far.
However, what in regards to the conclusion? Are you positive concerning the source?
Hi there every one, here every one is sharing these knowledge,
therefore it’s good to read this weblog, and I used to pay a
quick visit this blog everyday.
Simply want to say your article is as astonishing.
The clearness in your post is just cool and i can assume you are an expert on this subject.
Well with your permission allow me to grab your RSS feed to keep up
to date with forthcoming post. Thanks a million and please
carry on the gratifying work.
Greetings! Very helpful advice within this post!
It’s the little changes that produce the most
significant changes. Thanks a lot for sharing!
I’m really loving the theme/design of your web site.
Do you ever run into any internet browser compatibility problems?
A small number of my blog audience have complained about
my website not working correctly in Explorer but looks great
in Firefox. Do you have any ideas to help fix this issue?
Hey would you mind stating which blog platform
you’re working with? I’m looking to start my own blog soon but I’m having a difficult time making a decision between BlogEngine/Wordpress/B2evolution and Drupal.
The reason I ask is because your design seems different then most blogs and I’m looking for
something unique. P.S Apologies for being off-topic but I had to ask!
Thanks for your personal marvelous posting! I seriously enjoyed reading it,
you happen to be a great author. I will be sure to bookmark your
blog and will come back in the foreseeable future. I want to encourage you
continue your great posts, have a nice afternoon!
Hi! Do you know if they make any plugins to safeguard against hackers?
I’m kinda paranoid about losing everything I’ve worked
hard on. Any tips?
Admiring the persistence you put into your site and detailed information you present.
It’s great to come across a blog every once in a while that isn’t the same out of
date rehashed information. Excellent read! I’ve bookmarked your site and I’m including your RSS feeds
to my Google account.
Fastidious answers in return of this matter with real arguments and
telling everything regarding that.
Its such as you learn my thoughts! You appear to grasp a lot about this, such as you wrote the book
in it or something. I feel that you just could do with
a few % to pressure the message home a little bit, however instead of that, this
is wonderful blog. An excellent read. I’ll definitely be back.
I all the time used to study paragraph in news papers but now as I am a user
of web thus from now I am using net for posts, thanks to web.
I have fun with, lead to I found just what I was having a look for.
You have ended my 4 day lengthy hunt! God Bless you man.
Have a great day. Bye
Hey, I think your website might be having browser
compatibility issues. When I look at your blog site in Firefox,
it looks fine but when opening in Internet Explorer, it has some overlapping.
I just wanted to give you a quick heads up!
Other then that, terrific blog!
Hey I know this is off topic but I was wondering if you knew of any
widgets I could add to my blog that automatically tweet my newest twitter updates.
I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some
experience with something like this. Please let me know
if you run into anything. I truly enjoy reading your blog and
I look forward to your new updates.
Thanks on your marvelous posting! I seriously enjoyed reading it,
you will be a great author. I will be sure to bookmark your
blog and will eventually come back very soon. I
want to encourage that you continue your great writing, have a nice evening!