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A common nitrate test, known as the brown ring test [2] can be performed by adding iron(II) sulfate to a solution of a nitrate, then slowly adding concentrated sulfuric acid such that the acid forms a layer below the aqueous solution. A brown ring will form at the junction of the two layers, indicating the presence of the nitrate ion. [3]
Corrosion of iron nail with coiled copper in medium with ferroxyl indicator. Ferroxyl indicator, or rust indicator, is a solution containing potassium hexacyanoferrate(III), phenolphthalein and sodium chloride.
Flame test of a few metal ions A flame test involves introducing a sample of the element or compound to a hot, non-luminous flame and observing the color of the flame that results. [ 4 ] The compound can be made into a paste with concentrated hydrochloric acid, as metal halides , being volatile, give better results. [ 5 ]
In June, Paper 3 of the Mathematics GCSE (Higher Tier, 1MA1/03) appeared to contain an exam question which was published in an AQA (another British exam board) Further Mathematics textbook. The exam question had the same diagram, values and answer as the question in the textbook. Pearson Edexcel said that they were investigating how this might ...
GCSE Bitesize was launched in January 1998, covering seven subjects. For each subject, a one- or two-hour long TV programme would be broadcast overnight in the BBC Learning Zone block, and supporting material was available in books and on the BBC website. At the time, only around 9% of UK households had access to the internet at home.
A metal ion in aqueous solution or aqua ion is a cation, dissolved in water, of chemical formula [M(H 2 O) n] z+. The solvation number , n , determined by a variety of experimental methods is 4 for Li + and Be 2+ and 6 for most elements in periods 3 and 4 of the periodic table .
The International Baccalaureate Diploma Programme (IBDP) is a two-year educational programme primarily aimed at 16-to-19-year-olds in 140 countries around the world. The programme provides an internationally accepted qualification for entry into higher education and is recognized by many universities worldwide.
The charge on the ion is +5 − 3 × 2 = −1, and so the formula is ClO − 3. The structure of the ion is predicted by VSEPR theory to be pyramidal, with three bonding electron pairs and one lone pair. In a similar way, The oxyanion of chlorine(III) has the formula ClO − 2, and is bent with two lone pairs and two bonding pairs.