Chem Factsheet Questions. ChemistryFactsheets may be copied free of charge by teaching staff or students. No part of these Factsheets may be reproduced. FREE SAMPLES. There are still LOTS of resources available for FREE on the A2 FREE. CHEMSHEETS.co.uk has lots of KS3, GCSE, AS & A2 resources (& answers). 78 Chem bonding in bio mol v2 - Google Drive. Chemical Bonding in Biological Molecules Bio Factsheet September 2000 Number 78 1 The contents of this Factsheet are. FREE. Type. Code. File. Answers. Technician Notes. Organic synthesis 1 - without arrows. FREE. Worksheet. A2 026. click. JOIN. Organic synthesis 1 - with arrows. FREE. Chem Factsheet 3 Reactions of Functional Groups - A Summary Hydroxy-nitrile compound Ketones Secondary Alcohol Secondary Alcohol reduction reduction nucleophilic addition. Be part of the discussion and get useful help and advice on the TSR forums: Has anyone got any chem factsheets? Chem Factsheet. 38. The Chemistry of Copper. Oxides. Copper forms two oxides, both of which are basic. Practical 8 - Preparation of Cu. SO4. 5. H2. OPour dil. Bonding Chem Factsheet 3 The diagram shows the. for%20Gary/Chem%20resources/05_BONDI.PDF [ Read. pesticides/factsheets/Glyphosate.pdf [ Read. H2. SO4into a beaker, heat it, and add Cu. O with stirring until nomore will dissolve. Filter off the excess Cu. O. Transfer the filtrate to anevaporating basin, place it on a tripod and gauze, and boil the solutionuntil crystals show signs of forming. Turn out the heat and allow thesolution to cool and crystallise. Filter off the crystals, wash them witha little deionised water, and dry. Free to move around). Definition : The electronegativity of an atom is the ability of its nucleus to attract electrons in a bond pair. Bonding Chem Factsheet 3. Chem Factsheet PDF - Free Ebook Download - ebookdig.biz is the right place for every Ebook Files. We have millions index of Ebook Files urls from around the world. Exam Hint - ‘Crystallisation’ is different from ‘evaporation to dryness’. The latter is not recommended because: •it gives poorly formed crystals; •there may not be enough water left to act as water of crystallisation,resulting in the formation of anhydrous copper(II) sulphate; •impurities leave solution with the Cu. SO 4 . 5. H 2 O contaminating it. Aqueous chemistry of copper(II)[Cu(H 2. O)6 ]2+(aq) takes part in acid- base reactions(deprotonation) with OH - (aq) and NH 3(aq), ligand substitution with Cl− (aq), precipitation with CO3. I − (aq). Practical 9 - Cu. IIsalts with OH- (aq)Add dilute Na. OH(aq) dropwise, with shaking, to a solution of acopper(II) salt. A gelatinous pale blue precipitate of hydrated copper(II)hydroxide is formed. Two protons are transferred from molecules of coordinated water to hydroxide ions: [Cu(H2. O)6]2+(aq) + 2. OH- (aq)→[Cu(OH)2(H2. O)4](s) + 2. H2. O(l) Exam Hint - Do not show this as a precipitation reaction. All transitionmetal ions, and Al. OH - (aq) and NH 3(aq) in acid- base(deprotonation) reactions. Divide the precipitate of copper(II) hydroxide into two portions. Toone portion addconcentrated Na. OH(aq) and notice that it dissolves togive a blue solution containing the tetrahydroxocuprate(II) ion: [Cu(OH)2(H2. O)4](s) + 2. OH- (aq)→[Cu(OH)4]2- (aq) + 4. H2. O(l)Remember - Although Cu. O is basic, Cu(OH)2is amphoteric. Heat the other portion of Cu(OH)2and see how the colour changes fromblue to black as the hydroxide decomposes into the oxide: [Cu(OH)2(H2. O)4](s)→Cu. O(s) + 5. H2. O(l) Remember - Nearly all metal hydroxides decompose into thecorresponding oxides on heating. The only ones which are stable toheat are those of the alkali metals. Copper(I) oxide, Cu. OThis compound is prepared by reducing copper(II) salts in alkalinesolution. Practical 3 - Preparation of copper(I) oxide. Pour into a boiling tube roughly equal volumes of Fehling’s solution A(copper(II) sulphate) and Fehling’s solution B (an alkaline solution of potassium sodium tartrate) and mix. Then add a few drops of ethanaland boil cautiously. The dark blue colour of the solution fades to give areddish brown precipitate of copper(I) oxide. A redox reaction occurs in which ethanal is oxidised to a salt of ethanoicacid while Cu. II, in the form of a complex tartrate, is reduced to Cu. Iwhichappears as Cu. O. Remember - This reaction is used in organic chemistry to distinguishbetween aldehydes and ketones. Ketones will not reduce Fehling’ssolution because, unlike aldehydes, they are resistant to oxidation. Copper(I) oxide is a reddish brown solid which is insoluble in water butsoluble in acids. Copper(I) oxide reacts with dilute sulphuric acid, dilutenitric acid and concentrated hydrochloric acid, but the productsare notcopper(I) sulphate, copper(I) nitrate and copper(I) chloride. Copper(I) sulphate and copper(I) nitrate disproportionate in water (see above), while copper(I) chloride dissolves in conc. HCl(aq) togive complex ions. Practical 4 - Cu. O with dilute H2. SO4. Add Cu. 2O to dilute sulphuric acid in a test tube and warm gently. Ablue solution of copper(II) sulphate is formed. The reddish brownsolidappearsto remain unaltered, but in fact changes from Cu. O to Cu. Practical 5 - Cu. O with dilute HNO3. Add Cu. 2O to dilute nitric acid in a test tube. On warming, the Cu. Odissolves to give a clear blue solution of Cu. SO4plus brown fumes of NO2. Caution! These fumes are toxic. From Practical 4, a red- browndeposit of Cu might be anticipated, but Practical 1 shows that Cudissolves in dil. HNO3. Practical 6 - Cu. O with concentrated HCl(aq)Add conc. HCl(aq) to a little Cu. O and heat to obtain a dark greenishbrown solution containing various chloro- complex ions of copper(I) (p 4). Copper(I) oxide is also attacked by concentrated aqueous ammoniabecause the NH3molecule is a ligand and can coordinate to the Cu+ion. Practical 7 - Cu. O with concentrated NH3(aq)Add conc. NH3(aq) to a little Cu. O in a test tube, warmgently, shakecarefully, and allow to stand. The solution above the unreacted Cu. Owill be blue. The diamminecopper(I) ion, [Cu(NH3)2]+, is formed, but. O2from the air oxidises this to the dark blue copper(II) complex,[Cu(NH3)4(H2. O)2]2+.+2. H+- 2. H+Copper(II) oxide, Cu. OCopper(II) oxide is a black solid that can be prepared by heating. Cu(OH)2, Cu. CO3or Cu(NO3)2. It is insoluble in water but dissolves indilute acids to give solutions of Cu.
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