Talk:Methyl orange

Untitled
Revised topic to multi-section. More detail from anyone would be appreciated.

wikify
if someone cares to take the trouble, this article needs to reformatted to conform to the other chemical-related articles. Shaggorama 23:13, 11 April 2006 (UTC)

Inconsistency?
The text says that the modified methyl orange's colours are grey and green, but the diagram shows colourless (?) and purple...? 86.148.60.205 20:14, 2 March 2007 (UTC)

When I used it recently for some chemistry coursework, the colours of screened methyl orange were (alkali)green to purple(acid). If someone could find a source that verifies this it could be fixed. Stealth Wilde (talk) 19:40, 1 April 2008 (UTC)

Incorrectness
That isn't the correct structure of methyl orange there! When it acts as a base, the H+ does not add itself onto the O- in the SO3 group, but instead into one of the 'middle' N's, causing a shuffle-round of elecrons converting the non-sulphate arene into a cyclohexdiene group and placing a + charge on the 'outmost' N. —The preceding unsigned comment was added by Luke1001 (talk • contribs) 18:31, 18 March 2007 (UTC).
 * The current chemical structure is correct. -- Ed (Edgar181) 15:25, 26 November 2010 (UTC)

neutral
what colour is Methyl orange in an neutral solution? --I.W 20:59, 26 March 2007 (UTC)
 * Yellow, as pH 7 is out of the range of its changes and so is in its closest colour, which is 4.4, being yellow.--82.0.164.177 17:32, 15 October 2007 (UTC)

Synthesis
I tried to find a decent page on the synthesis of this stuff, but came up empty. I think some information on the synthesis of methyl orange would be helpful as it is a common thing made in organic chemistry lab

Grey or Purple for Xylene solution?
The article states that:
 * an indicator consisting of a solution of methyl orange and xylene cyanol, changes from grey to green as the solution becomes more basic

However, the color shown in the box illustration is purple. Ileanadu (talk) 18:21, 6 April 2011 (UTC)

pKa not pHa
At present, the article says:
 * Methyl orange has a pHa of 3.47 in water at 25 C

However I think pHa is intended to be pKa. Should we change? Buzzbo (talk) 23:12, 14 March 2016 (UTC)