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91
Organic Chemistry Forum / Re: Demurcuration Radical Mechanism
« Last post by hollytara on February 25, 2020, 04:44:03 PM »
The mechanism I have seen has these steps:

Hydride ion (H-) from borohydride displaces the acetate on mercury to form R-Hg-H

Homolytic cleavage of R-Hg bond.

Transfer of H radical to carbon radical from Hg-H to form R-H bond (C-H) and free mercury metal. 

This was established by Whitesides back in 1970. 

https://pubs.acs.org/doi/pdf/10.1021/ja00725a039 
92
Organic Chemistry Forum / Re: Making glacial acetic acid
« Last post by gatewood on February 25, 2020, 04:36:00 PM »
From WIKI
Quote
acetic acid

Melting point   16 to 17 °C; 61 to 62 °F; 289 to 290 K
Boiling point   118 to 119 °C; 244 to 246 °F; 391 to 392 K
Solubility in water Miscible

Solvent properties
Liquid acetic acid is a hydrophilic (polar) protic solvent, similar to ethanol and water. With a moderate relative static permittivity (dielectric constant) of 6.2, it dissolves not only polar compounds such as inorganic salts and sugars, but also non-polar compounds such as oils as well as polar solutes. It is miscible with polar and non-polar solvents such as water, chloroform, and hexane. With higher alkanes (starting with octane), acetic acid is not miscible at all compositions, and solubility of acetic acid in alkanes declines with longer n-alkanes.[21] The solvent and miscibility properties of acetic acid make it a useful industrial chemical, for example, as a solvent in the production of dimethyl terephthalate.[9]

yeah well, that doesn't help much. I found out that, it is possible to obtain high concentrations (up to 75%) using freezing destillation, if anyone is also interested.
93
High School Chemistry Forum / Re: Halogenations reactions
« Last post by chenbeier on February 25, 2020, 03:28:00 PM »
Yes correct calculation.
94
High School Chemistry Forum / Re: Halogenations reactions
« Last post by Helly on February 25, 2020, 03:26:02 PM »
Known : 2 moles Cl2 reacted with Alkene named A, it means the Alkene reacted also 2 moles,

Because in halogenation the mole ratio of

alkene : halogen : product = 1:1:1

2 moles of A reacted with Br2, has product of 460 g

Mass of A + mass of Br2 = 460 g
Mass of A = 460 - 320 = 140 g

2 moles of A has mass of 140 g.
Mr A = 70 g/moles
Alkene A is C5H10
95
High School Chemistry Forum / Re: Halogenations reactions
« Last post by chenbeier on February 25, 2020, 03:07:52 PM »
No you should post your calculation.
96
High School Chemistry Forum / Re: Halogenations reactions
« Last post by Helly on February 25, 2020, 03:04:45 PM »
Yes, thanks
97
High School Chemistry Forum / Re: Cumene process
« Last post by Helly on February 25, 2020, 03:03:49 PM »
Yes, you are right , that makes sense
98
High School Chemistry Forum / Re: Halogenations reactions
« Last post by chenbeier on February 25, 2020, 02:59:21 PM »
So now calculate further. What does it mean how many mol bromine. What mass was added and what is the mass of A.
From this you can calculate how much mole A and also the amount of C- atoms.
99
High School Chemistry Forum / Diluting vinegar
« Last post by Helly on February 25, 2020, 02:53:59 PM »
Given : Suppose the concentration of vinegar is to be diluted precisely to 1/10 with the aid of a
volumetric flask and an apparatus A, pipet or buret, which is wet as it has been washed
with distilled water. Whats the name of apparatus A used and the method of using it.

Key answer : pipet, to use after rinsing several times with the vinegar to be diluted

Can anyone tell me what they do in the question? I dont even understand the question..

Also the key answer : rinsing with the vinegar, whats to be diluted?
100
High School Chemistry Forum / Re: Cumene process
« Last post by Corribus on February 25, 2020, 02:50:35 PM »
Does it matter? You just need a balanced equation between the starting materials and finished products. If you don't know, you can find this by googling the cumene process. After you have a balanced chemical equation, it's just a straightforward stoichiometry problem.

(Also, check your units. You are mixing kg with g.)
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