<< Chapter < Page Chapter >> Page >

Method:


  1. Prepare 2 test tubes with approximately 5 ml of dilute Cu(II) chloride solution in each
  2. Prepare 1 test tube with 5 ml sodium carbonate solution
  3. Prepare 1 test tube with 5 ml sodium sulphate solution
  4. Carefully pour the sodium carbonate solution into one of the test tubes containing copper(II) chloride and observe what happens
  5. Carefully pour the sodium sulphate solution into the second test tube containing copper(II) chloride and observe what happens

Results:


  1. A light blue precipitate forms when sodium carbonate reacts with copper(II) chloride
  2. No precipitate forms when sodium sulphate reacts with copper(II) chloride

It is important to understand what happened in the previous demonstration. We will look at what happens in each reaction, step by step.

  1. Reaction 1: Sodium carbonate reacts with copper(II) chloride.
    When these compounds react, a number of ions are present in solution: Cu 2 + , Cl - , Na + and CO 3 2 - . Because there are lots of ions in solution, they will collide with each other and may recombine in different ways. The product that forms may be insoluble, in which case a precipitate will form, or the product will be soluble, in which case the ions will go back into solution. Let's see how the ions in this example could have combined with each other:
    Cu 2 + + CO 3 2 - CuCO 3
    Cu 2 + + 2 Cl - CuCl 2
    Na + + Cl - NaCl
    2 Na + + CO 3 2 - Na 2 CO 3
    You can automatically exclude the reactions where sodium carbonate and copper(II) chloride are the products because these were the initial reactants. You also know that sodium chloride ( NaCl ) is soluble in water, so the remaining product (copper carbonate) must be the one that is insoluble. It is also possible to look up which salts are soluble and which are insoluble. If you do this, you will find that most carbonates are insoluble, therefore the precipitate that forms in this reaction must be CuCO 3 . The reaction that has taken place between the ions in solution is as follows:
    2 Na + + CO 3 2 - + Cu 2 + + 2 Cl - CuCO 3 + 2 Na + + 2 Cl -
  2. Reaction 2: Sodium sulphate reacts with copper(II) chloride.
    The ions that are present in solution are Cu 2 + , Cl - , Na + and SO 4 2 - . The ions collide with each other and may recombine in different ways. The possible combinations of the ions are as follows:
    Cu 2 + + SO 4 2 - CuSO 4
    Cu 2 + + 2 Cl - CuCl 2
    Na + + Cl - NaCl
    Na + + SO 4 2 - Na 2 SO 4
    If we look up which of these salts are soluble and which are insoluble, we see that most chlorides and most sulphates are soluble. This is why no precipitate forms in this second reaction. Even when the ions recombine, they immediately separate and go back into solution. The reaction that has taken place between the ions in solution is as follows:
    2 Na + + SO 4 2 - + Cu 2 + + 2 Cl - 2 Na + + SO 4 2 - + Cu 2 + + 2 Cl -

[link] shows some of the general rules about the solubility of different salts based on a number of investigations:

General rules for the solubility of salts
Salt Solubility
Nitrates All are soluble
Potassium, sodium and ammonium salts All are soluble
Chlorides, bromides and iodides All are soluble except silver, lead(II) and mercury(II) salts (e.g. silver chloride)
Sulphates All are soluble except lead(II) sulphate, barium sulphate and calcium sulphate
Carbonates All are insoluble except those of potassium, sodium and ammonium
Compounds with fluorine Almost all are soluble except those of magnesium, calcium, strontium (II), barium (II) and lead (II)
Perchlorates and acetates All are soluble
Chlorates All are soluble except potassium chlorate
Metal hydroxides and oxides Most are insoluble

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
What makes metals better to use as wires than non-metals? (please link to bonding type)??? HELP
Yash Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Chemistry grade 10 [caps]. OpenStax CNX. Jun 13, 2011 Download for free at http://cnx.org/content/col11303/1.4
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Chemistry grade 10 [caps]' conversation and receive update notifications?

Ask