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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: unkwown on November 23, 2006, 05:05:31 PM

Title: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 05:05:31 PM
Hi i have an equation

 CaCO3 + 2HCl -> CaCl2 + CO2 + H2O

how would this look ionically???? I dont know which ones are the spectator ions. I looked in textbox and on internet but i cant quite get it. I came up with

Ca(2+)CO3(2-) -> Ca (2+)Cl2 (-) + H2O

i think that is wrong

thanks for help
Title: Re: Spectator ions (URGENT)
Post by: Albert on November 23, 2006, 05:18:27 PM
How soluble is calcium chloride?  ;)

http://en.wikipedia.org/wiki/Spectator_ion
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 05:31:54 PM
im still not sure. ive got my equation to

O3(2-) + 2H(+)Cl(-) -> Cl2 + O2 + H2O

but this cant be right

Can you give me the equation and tell me how you did it

thanks
Title: Re: Spectator ions (URGENT)
Post by: Albert on November 23, 2006, 05:38:54 PM
First of all, have you understood which are the spectator ions?

Quote
Ca(2+)CO3(2-) -> Ca (2+)Cl2 (-)

This is correct. For what concerns the rest, remeber that H2CO3-> H2O + CO2.

I can't give you the answer because of the rules of the website: we help people this way here.
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 05:45:02 PM
i know what a spectator ion is and i understand http://www.wpbschoolhouse.btinternet.co.uk/page01/ElCpdMix/EleCmdMix.htm#higher

EDIT: but can somebody please take me through this equation. I cant work it out
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 05:51:22 PM
H2CO3-> H2O + CO2.

hmm

i can understand the 3 oxygens are split and the 1 combines with 2 hydrogens to make water, but how would the equation look

thanks
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 05:53:55 PM
is this the ionic equation:

O3(2-) + 2H(+) -> CO2 + H2O

???
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 06:12:52 PM
nope wait...

i think its

C(4+)O3(2-) + 2H(+) -> CO2 + H2O

both have a charge of 0

can someone confirm that my ionic equation is right

Thankyou
 ;D

EDIT: or is it
2H(+) - > H2O
Title: Re: Spectator ions (URGENT)
Post by: Borek on November 23, 2006, 06:15:12 PM
1. CaCO3 is insoluble (well, it is weakly soluble, but you may assume it is insoluble) - thus it goes as CaCO3 into the equation.

2. Your original equation contains only two substances that will be completely dissociated and should be written as ions - which two?
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 06:21:10 PM
calcuim and chlorine? Am i right? So my equation: C(4+)O3(2-) + 2H(+) -> CO2 + H2O is right or wrong?
Title: Re: Spectator ions (URGENT)
Post by: Borek on November 23, 2006, 06:34:21 PM
calcuim and chlorine? Am i right? So my equation: C(4+)O3(2-) + 2H(+) -> CO2 + H2O is right or wrong?

Equation is wrong.

Calcium and chlorine are elements, I have asked about substances (compounds) that dissociate.
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 06:35:22 PM
im lost. Can't you just give me the equation and take me through how you got it?
Title: Re: Spectator ions (URGENT)
Post by: Borek on November 23, 2006, 06:40:33 PM
CaCO3 goes into the equation as solid.

HCl is strong acid, dissociated 100% - what ions are created?

CaCl2 is a soluble salt - dissociated as well - what ions are created?
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 06:44:29 PM
Quote
Your original equation contains only two substances that will be completely dissociated and should be written as ions - which two?

The only substance i can find that is disacciated is CalcuimChloride. Is CarboneDioxide the other one?? Meaning my final equation is

2H(+) - > H2O

what am i doing wrong?
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 23, 2006, 06:49:02 PM
Quote

CaCO3 goes into the equation as solid.

HCl is strong acid, dissociated 100% % - what ions are created
CaCl2 is a soluble salt - dissociated as well - what ions are created?
 


Hydrogen Ions react  with the O(-) ions. Hydrogen ions make somthing acidic and O(-) ions make somthing a base. Are the ions created H(+) Cl(-) and Ca(2+) Cl(-)???

Title: Re: Spectator ions (URGENT)
Post by: Borek on November 23, 2006, 06:56:55 PM
No such thing as O- ions, you probably mean OH-. They are of no use here.

Are the ions created H(+) Cl(-) and Ca(2+) Cl(-)???

Yes. Finally we are moving ahead ;)

Now, ALL you have to do is to rewrite the original reaction (the one you have posted in your very first letter) putting these dissociated substances into it. Don't touch CaCO3, nor CO2 nor water.
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 24, 2006, 04:56:49 PM
Can i just clarify is calcuim an ion? Calcuim is an element right wanting to lose 2 electrons to make outershell complete. Why do i write it as an ion, with the 2+ above it? It hasn't lost any electrons.

I can only get my equation down to
Ca(2+)CO3(2-) -> Ca (2+)Cl2 (-)

From my orginal question, which ions are the spectator ions?
Title: Re: Spectator ions (URGENT)
Post by: Albert on November 24, 2006, 05:16:31 PM
Don't touch CaCO3, nor CO2 nor water.

What's left among the products?  ;)
Title: Re: Spectator ions (URGENT)
Post by: Borek on November 24, 2006, 07:58:01 PM
Can i just clarify is calcuim an ion? Calcuim is an element right wanting to lose 2 electrons to make outershell complete. Why do i write it as an ion, with the 2+ above it? It hasn't lost any electrons.

I can only get my equation down to
Ca(2+)CO3(2-) -> Ca (2+)Cl2 (-)

From my orginal question, which ions are the spectator ions?

Calcium in calcium carbonate is already in ionic form - but, as the salt is insoluble, you don't write it as ion.

In the final equation please don't use form Ca(2+)Cl2(-) as it is probably source of the part of the confusion. What you have is Ca2+ + 2 Cl-.
Title: Re: Spectator ions (URGENT)
Post by: Borek on November 24, 2006, 07:59:58 PM
Don't touch CaCO3, nor CO2 nor water.

What's left among the products?  ;)

I am afraid you are not helping, but just adding to the unkwown confusion. His original equation listed all correct products, not necesarilly in the ionic form. But H2O and CO2 were OK.
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 25, 2006, 10:28:42 AM
can we start again  :-\

I have the equation:

CaCO3                 + 2HCl                  -->   CaCl2                + H20
Calcuim Carbonate + Hydrochloric Acid -->   Calcuim Chloride + Water

which goes to:
Ca(2+)CO3(2-) -> Ca (2+)Cl2 (-) + H2O

is this correct so far?

Can i asK:

Calcuim is an element right wanting to lose 2 electrons to make outershell complete. Why do i write it as an ion, with the 2+ above it? It hasn't lost any electrons yet??

Thankyou
Title: Re: Spectator ions (URGENT)
Post by: Alberto_Kravina on November 25, 2006, 10:32:38 AM
Quote
Calcuim is an element right wanting to lose 2 electrons to make outershell complete. Why do i write it as an ion, with the 2+ above it? It hasn't lost any electrons yet??
Calcium tends to lose 2 electrons, yeah, but in the carbonate it has already lost it's valence electrons, so it is impossible for the charged ion to lose other 2 electrons!
Title: Re: Spectator ions (URGENT)
Post by: tbuihuu on November 26, 2006, 06:56:59 AM
Quote
CaCO3                 + 2HCl                  -->   CaCl2                + H20
Calcuim Carbonate + Hydrochloric Acid -->   Calcuim Chloride + Water

which goes to:
Ca(2+)CO3(2-) -> Ca (2+)Cl2 (-) + H2O
it isn't correct. Only strongly dissociation substance may be change to ionic. so you can't write CaCO3 to Ca2+CO32-.And that reaction can be write:
CaCO3   +  2H+  ---> Ca2+  +  CO2  +  H2O
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 27, 2006, 04:01:55 PM
When you talk about a dissociation substance, do you mean a compound that has been bonded ionoically? Ive never heard of the term dissociation (maybe it's a amercianism?)
Title: Re: Spectator ions (URGENT)
Post by: Alberto_Kravina on November 28, 2006, 01:27:29 PM
http://en.wikipedia.org/wiki/Dissociation_%28chemistry%29
Title: Re: Spectator ions (URGENT)
Post by: unkwown on November 28, 2006, 04:35:03 PM
cheerz. Another question:

a isotope is define: Nuclei containing the same number of protons but different numbers of neutrons. Most elements can exist in several isotopic forms. A common example of an isotope is deuterium, which differs from normal hydrogen by the presence of an extra neutron in the nucleus.


but in the perodic table loads of element have a different number of neutrons to protons:

 Al has 14 protons and 13 neutrons, does this make it an isotope.

isn't hydrogen a isotope

But i've search and hydrogen isn't a isotope, the first one is deuterium

are about half the elements isotopes then?
Title: Re: Spectator ions (URGENT)
Post by: Borek on November 28, 2006, 05:15:12 PM
Don't post different question in an old thread, start new one whe the question is new.

Every atom is an isotope.

Hydrogen has three isotopes - hydrogen (sometimes called protium), deuterium and tritium. In fact there are much more hydrogen isotopes, but these three are most important.
Title: Re: Spectator ions (URGENT)
Post by: Dan on November 28, 2006, 05:37:23 PM
a isotope is define: Nuclei containing the same number of protons but different numbers of neutrons.

..

but in the perodic table loads of element have a different number of neutrons to protons:

You have misunderstood the definition.

The tree most important isotopes of H, as Borek has already said, are protium, deuterium and tritium

Protium ("normal" hydrogen): 1 proton, 0 neutrons
Deuterium: 1 proton, 1 neutron
Tritium: 1 proton, 2 neutrons.

Now, all three have the same number of protons in the nucleus (1) but the number of neutrons vary, so protium, deuterium and tritium are said to be isotopes of hydrogen.

In the same way, 35Cl and 37Cl (the superscript number is the atomic mass) are isotopes of Cl. Both have 17 protons, but the number of neutrons differ. These are the main isotopes of Cl, and exist in a 3:1 ratio of 35Cl to 37Cl (approximately), which is why the atomic mass of Cl is quoted on periodic tables as about 35.5.