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Hi guys,

I am trying to make a 1 M solution of ammonium hydroxide (NH4OH) from a 25% stock solution. My problem is that every reference I come across (The Laboratory, various chemistry sites online) says that the molecular weight of the compound should be 35.1, yet the bottle I have states that the M.W. is 77.08. Why is there a difference and should I trust the bottle or not? The bottle is from Silform and is labelled Ammonia solution 25% tech. It then has the formula NH4OH.

Zoe

Ammonium acetate has the molecular weight of 77.08.
I wouldn't trust the bottle. I've bought chemicals from Silform before and they've been wrongly labelled.
Try contacting Silform for their advice.

Ammonium Hydroxide is Ammonia page 35 from csis The Lab book page 11 tells us Ammonia is 17.0 Is that any help.

Hmm, the plot thickens. I think I will try contacting Silform...

Thanks.

In my recipe book I have dilution figures for Ammonia at different percentages to make 1M.
From memory I sourced this information from reliable sources many years ago when I made up my table.
10% 178ml reagent/822 water for a litre volume
18% 105 ml/895 water
25% 75ml/925 water
28% 68ml/932 water
35% 55ml/945 water.
I also have a note that I wrote stating that different sources of reference may have slightly different figures, however for the purposes of school chemistry these very slight differences do not matter.

Hi all,
I'm a little confused with ammonia...
We have some droppers labelled Ammonia solution 0.1m, and then we have ammonium hydroxide solution 0.1m.
I was having a google and I'm not 100% sure but is ammonia the same as ammonium hydroxide? Or is ammonia the gas and ammonium hydroxide the solution?
Should I be relabeling?
Help! Thanks in advance

labbassistant wrote: ↑12 Dec 2022, 08:39 Hi all,
I'm a little confused with ammonia...
We have some droppers labelled Ammonia solution 0.1m, and then we have ammonium hydroxide solution 0.1m.
I was having a google and I'm not 100% sure but is ammonia the same as ammonium hydroxide? Or is ammonia the gas and ammonium hydroxide the solution?
Should I be relabeling?
Help! Thanks in advance

Any diluted solution of ammonia is ammonium hydroxide. A bottle can be labelled with either, and programs like RiskAssess just list it as ammonia. As long as you are aware they are the same thing and can provide it no matter how the teachers ask for it, feel free to label it however you please

ottenc wrote: ↑12 Dec 2022, 10:42

labbassistant wrote: ↑12 Dec 2022, 08:39 Hi all,
I'm a little confused with ammonia...
We have some droppers labelled Ammonia solution 0.1m, and then we have ammonium hydroxide solution 0.1m.
I was having a google and I'm not 100% sure but is ammonia the same as ammonium hydroxide? Or is ammonia the gas and ammonium hydroxide the solution?
Should I be relabeling?
Help! Thanks in advance

Any diluted solution of ammonia is ammonium hydroxide. A bottle can be labelled with either, and programs like RiskAssess just list it as ammonia. As long as you are aware they are the same thing and can provide it no matter how the teachers ask for it, feel free to label it however you please

Amazing! Thank you so much!!