9 replies to this topic

[Vic]

Science homework

I know this isn’t pyrotechnics guys but hope some of you will know more about this subject than me. My son has to answer a question for his homework by Tuesday morning and his research on the web isn’t answering the question fully.Can anyone point him in the right direction or better still answer the question.

Which is;

Work out ways of making lead chloride.
Include word equations and general equations for all possibilities.
Must be done by acid + alkali /metal + acid/acid + base/metal carbonate + acid
Explore all those options with a balanced equation.
Explain why those that wont work don’t.[solubility issues]
Give a full experiment plan for the method that will work

Tom has come up with one option:
Metal carbonate + acid –salt + carbon dioxide + water
Pb CO3 +2HCl-PbCl2 + CO2 +H2O

Can anybody help. Thanks in advance Vic.

[Arthur Brown]

http://en.wikipedia....i/Lead_chloride

[Vic]

Hi there. Tom here.

I've already had a look at wikipedia, and that was what pointed me in the direction of the one idea I have got (The Pb CO3 +2HCl->PbCl2 + CO2 +H2O idea). However, from what I could understand of it the other ways suggested on wikipedia were done by reacting an existing salt with an acid, which is not what my teacher was looking for unfortunately.

I need to find ways of doing it by reacting an acid with an alkali, base or metal. These are somewhat harder to find, as they may not work and I have to say why they will not in this piece of work. I'm not sure, but there is every chance the methods of making Lead Chloride I am looking for will not work, and this might be why they are not turning up in any lists.

Thank you very much for having a read, even if the problem is not yet solved.

Best regards,
Tom.

[crystal palace fireworks]

Will this help?



http://www.gcsescien...ion.htmlons.htm

[Vic]

That site does appear to have alot of useful information, particularly the bits I'm looking for as it is intended specifically for GCSE science.

Thank you very much for the link, I think that website should manage to get me through this piece of homework.

Best regards,
Tom.

[Gillard]

hi.

i'm a chemistry teacher so here goes

Lead chloride is an insoluble salt and therefor can be made by a precipitation reaction between two soluble salt solutions.

eg

Lead nitrate +sodium cloride -> lead chloride +sodium nitrate.



the sodium nitrate is soluble, so the lead chloride can be separated by filtration, wash with distilled water first and then dried by GENTLE warming.

[Gillard]

just re read the question.

lead + acid Lead is too unreactive so will not react under normal conditions

lead oxide + acid - possibly but not a good method, reaction is very slow, Lead oxide would have to be powdered and acid would have to be hot. acid in excess so all lead oxide removed to allow filtration of insoluble lead chloride.

lead carbonate + acid - as above

Lead hydroxide - don't think this exists.

i suspect that the teacher has set a question where the above four methods are not really suitable for making lead chloride and then in the next lesson (s)he will introduce precipitation reactions.

do you know what exam board your son is sitting/

[Mixologist]

And my teacher always told me to read and then re-read the question before i answered ;o)

[Vic]

Hello, Tom again.

Thank you for the help, Gillard. I think between your explanation of this and the helpful link from Crystal Palace Fireworks, I should be able to get through this piece of homework.

I do get the impression that the lessons will be moving in the direction of different methods fairly soon and that this may be leading towards it. However, it's hard to tell if this homework is intended to lead on to that or not as my teacher has a habit of setting more difficult or confusing homework. The chemistry work I have done so far in year 11 has proven to be the hardest science work I have seen as yet, although this might be down to the teacher (I'm not having trouble with any of the other work at the moment)

I am doing the AQA exams, by the way.

Thanks again.

Best regards,
Tom.

[Gillard]

AQA acid topic has making lead chloride by mixing two solutions. the exams usually just have the 4 general acid equations, at higher tier you will have to do symbol equations.
if you have any problems, then feel free to PM me