Lab Experiment for Preparation of Ammonia

In summary: I'm sorry to hear that you're having trouble with the experiment. It sounds like you may not have added enough water to the mixture. Ammonium chloride and calcium hydroxide are both fairly soluble in water, so adding too much can make the mixture into a paste rather than a liquid. Need help on identifying the failure of the experiment and suggestions on the rectifications needed to make the experiment sucessfulrgdsBhuvanaIn summary, the experiment failed to produce any ammonia despite visible gas flow from the round bottom flask to the decicator. It is likely that the mixture of ammonium chloride and calcium hydroxide was too soluble and did not react as expected. There is a solution available for Lead
  • #1
bhuwana65
7
0
Hello ,
We tried to demonstrate preparation of Ammonia by mixing Ammonium Chloride and Calcium Hydroxide in round bottom flask mixed in the proportion of 2:3 .
The flask was in a slanting position with the delivery tube attached to a decicator with Calcium Oxide for drying the gas.
A Flask was attached to the outlet of the decicator for gas collection.

There was no resultant ammonia collected in the collection flask despite a visible flow of gas from the round bottom flask to the decicator on heating.

Need help on identifying the failure of the experiment and suggestions on the rectifications needed to make the experiment sucessful

rgds
Bhuvana
bhuwana65@yahoo.com
 
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  • #2
You need to heat your solution (you did add water right?) of ammonium chloride and calcium hydroxide. Calcium hydroxide is rather insoluble so it's rather weak at making ammonia, but at near boiling temperatures it should definitely work.
 
  • #3
How did you test for the presence of Ammonia in the collection flask?
 
  • #4
Thanks for your prompt replies .
My replies as below :
1) since water is produced during the reaction I did not add water . If water is to to be added please advice on the proportion to be added.
2) the presence of ammonia was tested using red litmus paper which turned blue initially .

Await your further help.
Regards
Bhuvana
 
  • #5
Cesium said:
You need to heat your solution (you did add water right?) of ammonium chloride and calcium hydroxide. Calcium hydroxide is rather insoluble so it's rather weak at making ammonia, but at near boiling temperatures it should definitely work.

Not so. The solubility of lime (calcium hydroxide) decreases as temperature increases. Lime has its highest solubility at near freezing temperature...
 
  • #6
bhuwana65 said:
Thanks for your prompt replies .
My replies as below :
1) since water is produced during the reaction I did not add water . If water is to to be added please advice on the proportion to be added.
2) the presence of ammonia was tested using red litmus paper which turned blue initially .

Await your further help.
Regards
Bhuvana

When testing for the presence of ammonia gas, it is best to wet the litmus paper.

You really need to add some water to your experiment. Sugar (sucrose) will aid the solubilization of lime. I would prepare a 10% sucrose solution and add that to the lime. Stir for 5 minutes or so and then add the ammonium chloride. The lime does not need to completely dissolve. I would use a 5:1 ratio of sucrose solution to lime. The amount of ammonium chloride should be 1.5 times the amount of the lime added.
 
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  • #7
Can anybody suggest a site which give details of various quantum numbers and order of filling up the orbitals (for Grade 11 students)
bhuwana
bhuwana65@yahoo.com
 
  • #8
chemisttree said:
Not so. The solubility of lime (calcium hydroxide) decreases as temperature increases. Lime has its highest solubility at near freezing temperature...

This is true, but increasing the temperature to increase the solubility was not my point. It is necessary to increase the temperature in order to increase the rate of reaction. I've performed a similar experiment before using ammonium nitrate and calcium hydroxide and at room temperature you only get a VERY weak smell of ammonia, but near boiling it really starts coming over.

So, bhuwana, I would suggest at least enough water to dissolve the ammonium chloride and to heat your solution. Calcium hydroxide works for producing ammonia but not as easily as more soluble hyroxides like sodium hydroxide.
 
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  • #9
Dear all,
Thanks a lot,my experiment withn ammonia preparation went off suceesfully and i could also perform fountain expt.
bhuwana
 
  • #10
What is the fountain experiment?
 
  • #11
chemisttree said:
What is the fountain experiment?
An exert from the “Golden Book of Chemistry” (1960),
http://i62.photobucket.com/albums/h104/mrjeffy321/PF/AF.jpg
 
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  • #12
For Class XII students ,I am conducting Qualitative salt analysis.While analysing various salt mixtures we had a problem with a particular mixture
It was Leadnitrate+Calcium carbonate.
The mixture does not dissolve in Cold Water/Hot water/Cold dilue Hcl/Hot Dilute Hcl.What i mean we do not get a clear solution to go to Group I,which is lead
In addition to that Lead precipates again In Group IVas lead sulphide in black colour( in presence of NH4cl+in excess of NH4OH+H2S).
It is very confusing.How to guide them .Pl.help
Bhuvana
 
  • #13
Lead is always a problem when you use HCL. The solubility product of lead chloride is 1.6X10^-5 so adding excess HCl to dissolve these will ultimately lead to problems.

Take your cue from the soluble salts of lead, especially nitrate. Try dissolving the calcium carbonate in nitric acid instead.

Good luck.
 
  • #14
Hi
I'm also trying to prepare Ammonia and can you all please just say how you prepare it again I kind of got lost.
Thanks
 
  • #15
uhh can anyone tell answer my question please. why is the mixture of ammonium chloride and calcium hydroxide a paste instead of a solution?
 
  • #16
Ayush Suwal said:
uhh can anyone tell answer my question please. why is the mixture of ammonium chloride and calcium hydroxide a paste instead of a solution?

Because you didn't add enough water to completely dissolve the solids.
 
  • #17
So u mean to say i got to add more water?
 
  • #18
chemisttree said:
Because you didn't add enough water to completely dissolve the solids.
but i got a question to answer here "Y IS THE MIXTURE A PASTE INSTEAD OF A solution
 
  • #19
Why is something not in solution? The general answer is that not enough solvent is used.

Why are we using the ingredients as a paste instead of a solution is a different question altogether... Think about the solubility of both ingredients briefly and see if something doesn't come to you.
 
  • #20
chemisttree said:
Because you didn't add enough water to completely dissolve the solids.

We were given paste instead of solution. The question goes like this "In the preparation of ammonia why is the mixture of ammonia Chloride and Calcium hydroxide a paste NOT a solution." and "Why can't anhydrous calcium chloride be used to dry ammonia"
 
  • #21
i do know about the solubility but we weren't allowed to tamper with it
 
  • #22
You do not need to have a paste or solution to get ammonia from the two mixtures. In fact as soon as one mixes the two, you could smell the characteristic ammonia vapour coming out. Ammonia. A mixture with two teaspoon fulls will produce enough ammonia for repeating it four times. Just make sure that you use a dry round bottom flask every time. Calcium oxide could be covered in lint and positioned near the mouth of the test tube.

Moisten the red litmus paper and place it near the mouth of the inverted round bottom flask.

For the fountain experiment, the reaction begins by injecting some water into the system and the fountain should always work!

Koroi
 

1. What is the purpose of the lab experiment for preparation of ammonia?

The purpose of this lab experiment is to demonstrate the synthesis of ammonia, a compound commonly used in fertilizers, household cleaners, and other industrial products. It also allows students to practice important laboratory techniques and gain a better understanding of chemical reactions.

2. What materials are needed for the preparation of ammonia?

The materials needed for this experiment include an ammonia generator, concentrated ammonia solution, hydrochloric acid, water, a pH meter, and various glassware such as beakers, flasks, and tubing. Safety equipment such as goggles and gloves should also be used.

3. What is the chemical equation for the preparation of ammonia?

The chemical equation for the preparation of ammonia is N2 + 3H2 → 2NH3, where nitrogen gas and hydrogen gas combine to form ammonia gas.

4. What is the optimal reaction conditions for the preparation of ammonia?

The optimal reaction conditions for the preparation of ammonia include a temperature of around 400-500 degrees Celsius and a pressure of 200-300 atmospheres. This allows for a higher yield of ammonia in a shorter amount of time.

5. What are some safety precautions to take during the preparation of ammonia?

Some safety precautions to take during this experiment include wearing goggles and gloves, working in a well-ventilated area, and avoiding direct contact with the chemicals. It is also important to handle the concentrated ammonia and hydrochloric acid with care, as they are corrosive. In case of any spills or accidents, be sure to follow proper protocol for clean-up and disposal.

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