All Questions
9
questions
7
votes
2
answers
642
views
Question about the differences of white and grey NaH properties
We are having some problems with the next reaction in our lab. As you can see, is the sulfonylation of an indole in which we use NaH (60% dispersion in mineral oil) as a base. This reaction goes with ...
- 81
0
votes
0
answers
165
views
Why is the pH of this ammonia solution more acidic than another ammonia solution?
I made two similar ammonia solutions in different ways, and they resulted in different pH, but i'm not sure why.
Solution 1
Added 5.84 g NaCl to a 500 mL flask. Then added 10 mL 25% ammonia solution. ...
- 11
-1
votes
1
answer
106
views
Will concentration of sodium hydroxide affect the result of chicken feather hydrolyzate if i don't standardized it?
The title of the paper:
Isolation and characterization of keratin from chicken feathers https://doi.org/10.1063/5.0002792
Here is the method:
Keratin was isolated by dissolving 5g of chicken feather ...
- 79
1
vote
0
answers
45
views
How do you purify phosphoric acid from cheap commercial (hardware-store) products?
I am looking for idea's on how to purify phosphoric acid for lab use, as the the price for reagent grade V's home-use ended with me buying a product designed as a rust-killer for steel... The ...
- 11
2
votes
0
answers
689
views
Deprotection (debenzoylation) of glucose (sacharide) using NaOMe leads to hydrolysis glucose
I have a problem removing the benzoyl groups of my glucose moiety using sodium methylate (standard procedure). Indeed, the benzoyl groups are removed. However, a significant amount of glucose gets ...
- 21
3
votes
1
answer
9k
views
Why is sodium potassium tartarate used in Fehling's solution?
Why is this salt used specifically in Fehling's solution, instead of a simple disodium or dipotassium salt of tartaric acid?
- 470
1
vote
1
answer
202
views
How to distinguish palmitic acid from lauric acid?
I'm reacting either palmitic acid or lauric acid ($\ce{C16H32O2}$ or $\ce{C12H24O2}$) with $\ce{NaOH}$, sodium hydroxide.
I'm wondering if there's any way to tell which one of those two acids it is ...
5
votes
2
answers
5k
views
Role of hydrochloric acid and sodium hydroxide in isolation of citric acid from lemon juice
I'm trying to extract citric acid from squeezed lemons.
After studying the subject, I found a lab manual [1, p. 68]:
ISOLATION OF CITRIC ACID
Reagents:
Lemon juice (ca. $\pu{100 mL}$ – 3 lemons)
$\...
- 51
3
votes
0
answers
2k
views
Lassaigne's test for sulfur
The sodium fusion extract is acidified with acetic acid and lead acetate is added to it. A black precipitate of lead sulphide indicates the presence of sulphur.
What is the need for acidification of ...
- 3,487