January 20, 2020, 03:52:01 AM
Forum Rules: Read This Before Posting


Recent Posts

Pages: [1] 2 3 ... 10
1
Dear mjc123,
attached my working.
2
As a part of a university course in analitical chem I was given a solution of MnSO4 and Co(NO3)2 and was asked to determain thier concentration , I tried oxidising the Mn+2 to MnO4 using H3PO4 and KIO4 , it worked , but then I tried to run a sepctroscopy test of the solution I got 3 peaks, which doesn't make alot of sence....

Dose any one know what could have happened ?

And I'd love to hear if you have any more ideas!

I thought about EDTA titration but I have no idea what range of pH to use , the book I'm using isn't that comprehansable
3
Organic Chemistry Forum / Sucrose Glycosidic Linkage!!
« Last post by jaysonmonroe on Today at 02:44:30 AM »
I'm currently reviewing ochem for my MCAT and came across a question in my TPR guide while going over glycosidic linkages. It lists sucrose as an alpha-1,2 linkage. I remember learning in biochem that it is an alpha-1, beta-2 linkage. I'm wondering if this is an error in my book or if it can take on both forms. The picture for reference also shows it as an alpha-1,2 linkage.

4
Water autodissociation is an equilibrium process and water ions product is just an equilibrium constant.

And its value is 10-14.

But that's exactly what changing the pH/making a solution acidic/basic is, so shouldn't that change the balance point of the reaction from water to oxoniumions and hydroxidions.

Because that would then result in a change of the ion product.

Quite the opposite, if one grows, the other must go down to keep the product constant.
5
Physical Chemistry Forum / Re: RO Concentrate Water parameters
« Last post by Borek on Yesterday at 03:25:29 PM »
In other way, is there any formula to calculate pH based on ionic strength of water?

Same way you would do with any activity calculations, see for example http://www.chembuddy.com/?left=pH-calculation&right=ionic-strength-activity-coefficients

Quote
Secondly, how to calculate conversion carbonate from bicarbonate???

It doesn't convert on its own, I have no idea what you are asking.
6
Hello guys,

I'm doing a presentation in school about pH and acids and bases. Right now, I have a question about the ion product of water and I hope some of you can help me out with that.

So, it's clear that the ion product in a neutral solution is 10^14. But for the equations about the potency of acids and bases, the ion product has to be the same as well because pKs + pKb = 14. But I don't understand why that's the case from a reaction's standpoint.

In school, we learnt that you can move the reaction balance point by increasing/decreasing the concentration of one of the educts/products.

But that's exactly what changing the pH/making a solution acidic/basic is, so shouldn't that change the balance point of the reaction from water to oxoniumions and hydroxidions.

Because that would then result in a change of the ion product.

Can someone make out where I'm wrong here? Thank you all very much, I greatly appreciate any *delete me*
7
High School Chemistry Forum / Re: acetylene gas + ammoniac silver nitrate
« Last post by MNIO on Yesterday at 01:32:50 PM »
your reaction is
  1 H-C≡C-H + 2 Ag[NH3]2NO3 ---> Ag-C≡C-Ag + ___

the Ag-C≡C-Ag is your silver acetylide and ppt's out as a grey to white solid depending on purity and particle size. 

***********
fyi.. silvery acetylide is a heat and shock sensitive explosive.  I would not recommend drying the product, or even running the reaction without extreme caution.
8
High School Chemistry Forum / Re: acetylene gas + ammoniac silver nitrate
« Last post by chenbeier on Yesterday at 11:25:04 AM »
You have to see, to know or to learn it.
The clean silveracetylid is white, but by producing of it some metal silver also precipitate so crued product is grey.
The copperacetylid is red like copper- I- oxide. Also here it can precipitate some copper metal  what also give the red copper colour.

PS: Dont perform these  Experiments. Very dangerous.

9
High School Chemistry Forum / acetylene gas + ammoniac silver nitrate
« Last post by Helly on Yesterday at 11:16:57 AM »
acetylene gas + ammoniac silver nitrate what color is the precipitate
the answer is white, why? i googled it, is the product is silver acetylide ? but it looks grey not white?

and acetylene gas + ammoniac copper 1 chloride, the answer is red. why? how to know what color is precipitate?
10
We need 0.2 M H2S ? For 0.1 M Cu2+ and 0.1 M Zn2+.

So in step 3 we add h2s again to make sure if theres still cation group 2?
Btw, what is the white percipitate from step 3 when we add h2s? There is left zn only in step 3 right? Since ag and cu been precipitate?
Pages: [1] 2 3 ... 10