[malteser16]

Hello,

I need some help to try to make lead nitrate please. I know it is done by mixing lead metal with nitric acid, but how do I calculate the proportions of each that I need to use?

the chemical formula is;

Pb + 2HNO₃  Pb(NO₃)₂ + 1/2 O₂ + NO₂

is it correct?

ok so I would need;

207g Pb for 126g HNO₃ am I correct?

now I was wondering....the above calculation is for 100% nitric acid but store bought nitric acid comes 65%, so how do I calculate the amount needed for the Lead Nitrate reaction using 65% nitric acid?

sorry if this is a childish question, but I'm new at chemistry. Thanks for all your *delete me*.

[Donaldson Tan]

Lead plus Nitric Acid is a bad way to make lead (II) nitrate because the lab procedure involves toxic fumes.

An alternative method to make lead (II) nitrate is mixing lead (II) oxide with nitric acid.

PbO (s) + 2 HNO₃ (aq) -> Pb(NO₃)₂ (aq) + H₂O (l)

[Arkcon]

Generally, when you try to "make" an inorganic compond from other ones, you don't try to get it stoichiometrically correct.  You usually have one reactant in greater excess, so it's left over, and then you remove it from your product.  Not that it's not cool to try and learn how the reaction formula can be used to see what amounts are needed, but you do have to have the knowledge to convert moles of reactants, to grams you can measure.  If you're real new to chemistry, you have lots of reading to do.

http://en.wikipedia.org/wiki/Stoichiometry

Then there's this fourm thread here:

http://www.chemicalforums.com/index.php?topic=30659.msg116606#msg116606

[malteser16]

Lead plus Nitric Acid is a bad way to make lead (II) nitrate because the lab procedure involves toxic fumes.

An alternative method to make lead (II) nitrate is mixing lead (II) oxide with nitric acid.

PbO (s) + 2 HNO₃ (aq) -> Pb(NO₃)₂ (aq) + H₂O (l)

thanks geodome for your reply. Yes NO_x is produced during my reaction but no worries I made a gas scrubber  and also lead metal powder is way much more cheaper than PbO, at least here in my country.

thanks also to Arkcon for your reply, yes I would put in excess nitric acid to convert all lead to lead (II) nitrate, anyways lead nitrate is insoluble in nitric acid am I right? but still I need to have at least an idea of how much i'm suppose to use from each chemical. As you say, it's very interesting to know what is going on during a reaction and also very safe due to it serves as a risk assessment also. Thanks also for those links and yes! i have a LOT of reading to do! 

[Arkcon]

I'm not certain that lead nitrate is insoluble in nitric acid.  Maybe, by common ion effect, it would be less soluble, but there should be plenty of water around, to dissolve them all.  I'd work it from the other way 'round.

[nj_bartel]

Yea, all nitrate salts are soluble in water, and as you aren't using highly concentrated nitric acid, a fair quantity would probably end up dissolving if you ran excess nitric acid instead of excess lead

[malteser16]

Yea, all nitrate salts are soluble in water, and as you aren't using highly concentrated nitric acid, a fair quantity would probably end up dissolving if you ran excess nitric acid instead of excess lead

I see, so it would be better if I used excess lead then filter the whole thing for purification, then I can get rid of the majority of the water by heating and the negligable remainder of water by a good dessicant such as CaCl₂ ....which brings me to my other job...I need to do some CaCl₂ then, I will make this by reacting Ca(OH)₂ with HCl which will give me aqeous CaCl₂ and I can get rid of the water again by heating, is this a good way of making CaCl₂?

Thanks all for your help.

[Fleaker]

The PbO method works quite nicely.

If I were doing it and I had lead powder and nitric acid, I would use 35% nitric acid (by mass), doing it outside or in a fume hood with a good draught. If your nitric is less dilute than the normal 16M/azeotropic reagent out of the bottle, it will do more work with less fumes. The nitrogen oxides, particularly the dangerous and acrid NO₂, will dissolve into the solution and oxidize more of your lead.

I would add only as much nitric acid as is necessary to completely dissolve the lead, and then perhaps a couple extra milliliters of nitric acid to keep it nice and acidic. If you do not keep it quite acidic, you run the risk of atmospheric CO₂ making lead carbonate; this is more if you plan on storing it for later use.

If you're going to crystallize out the lead (II) nitrate, then you should just set it to a boil (in a tall beaker so as to avoid spattering toxic lead nitrate all around) and make a nice saturated solution. Pour this into a crystallization dish and hopefully it will crystallize. If it doesn't, scratch the bottom of the dish with a quartz rod, if it still doesn't come out, perhaps try putting the dish on a hot plate and slowly heating it to drive off water.

Good luck, I hope you do some cool experiments with it!
Fleaker