DE THI OLYMPIC TIN HOC QUOC TE

... laboratory desk determine the content of the individual test-tubes. Give reasons for both the tests performed and your answers and write the chemical equations of the corresponding reactions. Note: ... glucose. Determine the order in which the substances in the test tubes are placed in your rack and give chemical reactions you used for identification of the substances. For identific...

Ngày tải lên: 06/04/2014, 15:41

... aldehyde B is subsequent to an aldehyde A in the homologous series of aldehydes. An amount of 19 g of aldehyde B is added to 100 g of an aqueous solution containing 23 mass % of aldehyde ... with 270 mg of water but only one third of water reacted. A basic solution was formed in which the content of hydroxides was 30 % by mass and at the same time deposited a precipitate with a mass...

Ngày tải lên: 06/04/2014, 15:41

... orthophosphate, barium hydroxide, lead nitrate, potassium hydroxide, aluminium sulphate, sodium carbonate. Using only these solutions as reagents, determine in which of the numbered test tubes each of ... numbered test tubes, 20 cm 3 each, contain 0.1 M solutions of the following substances: barium chloride, sodium sulphate, potassium chloride, magnesium nitrate, sodium orthophosphate, b...

Ngày tải lên: 06/04/2014, 15:41

... gravimetric determination yielded a precipitate of which 12 % by mass was decomposed by light. Determine the size and direction of the error caused by this decomposition. 4.3 Consider a solution ... diastereotopic methylene protons at the double bond of A was selectively substituted by deuterium. Bromination and subsequent dehydrobromation yields the deuteriated product B and the non...

Ngày tải lên: 06/04/2014, 15:42

... with deionised water. Pipette 20.00 cm 3 of this solution into a 300 cm 3 Erlenmeyer flask and dilute to about 100 cm 3 with deionised water. Back titrate the residual sodium hydroxide with ... places after decimal point.) Procedure : Pipette 20.00 cm 3 of the sodium hydroxide solution into a 300 cm 3 Erlenmeyer flask and dilute it to about 100 cm 3 with deionized water. Titrate...

Ngày tải lên: 06/04/2014, 15:42

... (use measuring cylinders for these solutions). Titrate the contents with the thiocyanate solution and determine the end-point according to the instruction given in the "Determination" ... disintegrates by a series of α -decays and β - -decays until it becomes 206 Pb, which is stable. i) How many α -decays and how many ß - -decays does an atom starting as 238 U undergo ......

Ngày tải lên: 06/04/2014, 15:42

... complete halt, the solution should be titrated immediately after the addition of the sodium acetate solution. The remaining iodine I 2 (aq) is determined by titration with sodium thiosulphate, ... provide a steady rate of distillation. At least 5 cm 3 of distillate must be collected. Hot plate must be turned off after distillation is finished. Disassemble the apparatus and rinse the con...

Ngày tải lên: 06/04/2014, 15:43

... the six stereoisomers 1-6 of B shown above did they isolate? After prolonged heating (15h, 120 °C) of the origin ally isolated stereoisomer B (melting point mp: 157 °C), Diels and Alder obtaine ... Argyrodite is m(Ag) : m(Y) = 11.88 : 1. Y forms a reddish brown lower sulfide (oxidation state of Y is +2) and a higher white sulfide (oxidation state of Y is +4). The coloured lower sulfid...

Ngày tải lên: 06/04/2014, 15:44

... B Giỏo Dc V o To Kè THI CHN I TUYN QUC GIA D THI OLYMPIC HO HC QUC T NM 2004 Thi gian : 240 phỳt ( khụng k thi gian giao ) Ngy thi th nht Cõu I: 1. Lu hunh trioxit SO 3 ... th rỳt ra kt lun gỡ? Cõu II: Tinh th bc cú cu trỳc lp phng tõm din. 1. Hóy v mt ụ mng n v (t bo c s). 2. Tớnh s nguyờn t trong mt ụ mng n v. 3. Xỏc nh hng s mng ca tinh th Ag. Bit bỏn kớnh nguyờn ... s axit p...

Ngày tải lên: 16/08/2013, 20:41

... bộ giáo dục và đào tạo Đề thi dự bị Thí sinh phải kiểm soát kĩ: Đề thi có 03 trang. kì thi chọn Học sinh vào đội tuyển dự thi olympic hoá học Quốc tế năm 2005 Thời gian : ... tuyển dự thi olympic hoá học Quốc tế năm 2005 Thời gian : 240 phút ( không kể thời gian giao đề ) Ngày thi thứ nhất : 09 / 5 / 2005 Câu 1 1. Cho dòng khí clo đi từ từ và liên tục qua dung dịch KI đựng...

Ngày tải lên: 16/08/2013, 20:42