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A-level chemistry ionic equations help!
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username3658760
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#1
Hi, how can you tell what a solid is in the reaction between ionic compounds. For example:
1) when aqueous magnesium chloride is added to aqueous silver nitrate, a white precipitate is formed.
Write out the full stoichiometric and ionic equations for the reaction.
The answer is: mgcl2(aq) + 2agno3 (ag) = mg (no3)2 (ag) + 2agcl (s).
I'm very confused because how did we know that the solid formed was silver chloride and not magnesium nitrate??? Is there a way to figure out what the precipitate (s) will be because I asked my teacher and she said no, you just 'know'. But how the **** in an exam are you supposed to know what the aqueous will be and what the solid formed will be. She said in this particular reaction that nitrate is always dissolves in solution so that's how you know that won't be a solid.
But other questions give you compounds like: barium chloride and sodium sulphate, what is the solid formed and how do you know that?
Thanks
1) when aqueous magnesium chloride is added to aqueous silver nitrate, a white precipitate is formed.
Write out the full stoichiometric and ionic equations for the reaction.
The answer is: mgcl2(aq) + 2agno3 (ag) = mg (no3)2 (ag) + 2agcl (s).
I'm very confused because how did we know that the solid formed was silver chloride and not magnesium nitrate??? Is there a way to figure out what the precipitate (s) will be because I asked my teacher and she said no, you just 'know'. But how the **** in an exam are you supposed to know what the aqueous will be and what the solid formed will be. She said in this particular reaction that nitrate is always dissolves in solution so that's how you know that won't be a solid.
But other questions give you compounds like: barium chloride and sodium sulphate, what is the solid formed and how do you know that?
Thanks
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sarah99630
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#2
(Original post by TSR69)
Hi, how can you tell what a solid is in the reaction between ionic compounds. For example:
1) when aqueous magnesium chloride is added to aqueous silver nitrate, a white precipitate is formed.
Write out the full stoichiometric and ionic equations for the reaction.
The answer is: mgcl2(aq) + 2agno3 (ag) = mg (no3)2 (ag) + 2agcl (s).
I'm very confused because how did we know that the solid formed as silver chloride and not magnesium nitrate??? Is there a way to figure out what the precipitate (s) will be because I asked my teacher and she said no, you just 'know'. But how the **** in an exam are you supposed to know what the aqueas will be and what the solid formed will be. She said in this particular reaction that nitrate is always dissolves in solution so that's how you know that won't be a solid. But other questions give you compunds like: barium chloride and sodium sulphate, what is the solid formed and how do you know that?
Thanks
Hi, how can you tell what a solid is in the reaction between ionic compounds. For example:
1) when aqueous magnesium chloride is added to aqueous silver nitrate, a white precipitate is formed.
Write out the full stoichiometric and ionic equations for the reaction.
The answer is: mgcl2(aq) + 2agno3 (ag) = mg (no3)2 (ag) + 2agcl (s).
I'm very confused because how did we know that the solid formed as silver chloride and not magnesium nitrate??? Is there a way to figure out what the precipitate (s) will be because I asked my teacher and she said no, you just 'know'. But how the **** in an exam are you supposed to know what the aqueas will be and what the solid formed will be. She said in this particular reaction that nitrate is always dissolves in solution so that's how you know that won't be a solid. But other questions give you compunds like: barium chloride and sodium sulphate, what is the solid formed and how do you know that?
Thanks
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ambershell27
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#3
Is the topic qualitative analysis? Your teacher is right.
To summarize the precipitate reactions:
When testing for sulfate ions, add aqueous barium ions. A white precipitate of barium sulfate forms.
When testing for halide ions, add aqueous silver ions. A precipitate of silver halide forms.
If you've covered sequence of tests, carbonates also precipitate barium, and sulfate precipitates with silver ions. It's just something you have to learn.
To summarize the precipitate reactions:
When testing for sulfate ions, add aqueous barium ions. A white precipitate of barium sulfate forms.
When testing for halide ions, add aqueous silver ions. A precipitate of silver halide forms.
If you've covered sequence of tests, carbonates also precipitate barium, and sulfate precipitates with silver ions. It's just something you have to learn.
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username3658760
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#4
(Original post by sarah99630)
you need to know which ones are soluble, there was a table showing that in the edexcel AS book I think, u can come up with a mnemonic to help u remember. eg all nitrates are soluble, and I think everything with potassium, lithium and sodium are always soluble as well. most compounds may have 2 or 3 exceptions so it will be easy to remember. eg all chlorides are soluble except with 2 or 3 metals (I forgot which ones, I guess lead and silver??) try to look for that table. hopefully it'll make sense. good luck!
you need to know which ones are soluble, there was a table showing that in the edexcel AS book I think, u can come up with a mnemonic to help u remember. eg all nitrates are soluble, and I think everything with potassium, lithium and sodium are always soluble as well. most compounds may have 2 or 3 exceptions so it will be easy to remember. eg all chlorides are soluble except with 2 or 3 metals (I forgot which ones, I guess lead and silver??) try to look for that table. hopefully it'll make sense. good luck!
, thanks anyway
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#5
(Original post by ambershell27)
Is the topic qualitative analysis? Your teacher is right.
To summarize the precipitate reactions:
When testing for sulfate ions, add aqueous barium ions. A white precipitate of barium sulfate forms.
When testing for halide ions, add aqueous silver ions. A precipitate of silver halide forms.
If you've covered sequence of tests, carbonates also precipitate barium, and sulfate precipitates with silver ions. It's just something you have to learn.
Is the topic qualitative analysis? Your teacher is right.
To summarize the precipitate reactions:
When testing for sulfate ions, add aqueous barium ions. A white precipitate of barium sulfate forms.
When testing for halide ions, add aqueous silver ions. A precipitate of silver halide forms.
If you've covered sequence of tests, carbonates also precipitate barium, and sulfate precipitates with silver ions. It's just something you have to learn.
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ambershell27
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#6
So she just expected you to remember from GCSE? Will you be doing more of the topic in class?
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#7
(Original post by ambershell27)
So she just expected you to remember from GCSE? Will you be doing more of the topic in class?
So she just expected you to remember from GCSE? Will you be doing more of the topic in class?
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Ah, I see. That's an odd task to do if you have no previous knowledge, but if you're going to cover it later, then that's good.
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#9
(Original post by ambershell27)
Ah, I see. That's an odd task to do if you have no previous knowledge, but if you're going to cover it later, then that's good.
Ah, I see. That's an odd task to do if you have no previous knowledge, but if you're going to cover it later, then that's good.
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