The two dots above and the two dots below are lone pairs of the O. When barium metal burns in oxygen, the ionic compound barium peroxide, Ba02, is formed. This reaction is the basis for the now-obsolete Brin process for separating oxygen from the atmosphere. 000 x x 00 x x ox x key electron from first oxygen atom electron from second oxygen atom electron from barium atom Skin cancer can be treated using a radioactive isotope of phosphorus, ISP . Other oxides, e.g. BARIUM PEROXIDE is a strong oxidizing agent. Contact with water can produce a temperature and oxygen concentration high enough to ignite organic materials [Bretherick's, 5th ed., 1995, p. 94]. Reacts explosively with acetic anhydride due to the formation of acetyl peroxide [Rust, 1948, p. 337]. The peroxide ion has the structure [O–O]2–. Suggest a ‘dot-and-cross’ diagram for BaO 2. H with a cross and a dot on the right hand side, showing that the H atom donates one electron and the O donates one electron to the single bond. Trimethylamine, Me 3 N, reacts with boron trifluoride, BF 3, to form a compound of formula Me 3 N.BF … 2 formed in Reaction 3 contains barium and peroxide ions. [1] [Total: 10] END OF QUESTION PAPER PMT The peroxide forms around 500 °C and oxygen is released above 820 °C. Which dot-and-cross diagram represents the electronic structure of the peroxide anion in BaO 2? Q7 In this question, the methyl group, CH3, is represented by Me. Then the first O atom, with two dots above, two dots below, and two on the right. Q7 In this question, the methyl group, CH 3, is represented by Me. Barium peroxide arises by the reversible reaction of O 2 with barium oxide. A Cl B CN C CO 2 CH 3 D OH Q6 When barium metal burns in oxygen, the ionic compound barium peroxide, BaO 2, is formed. Na 2 O and SrO, behave similarly. Which dot-and-cross diagram represents the electronic structure of the peroxide anion in BaO2? Show outer shell electrons only. Q6 When barium metal burns in oxygen, the ionic compound barium peroxide, BaO2, is formed. Which dot-and-cross diagram represents the electronic structure of the peroxide anion in Ba02? 2 BaO + O 2 ⇌ 2 BaO 2. Ignites when mixed with powdered aluminum, powdered magnesium or calcium-silicon alloys. 3 © UCLES 2008 9701/01/M/J/08 [Turn over 4 When barium metal burns in oxygen, the ionic compound barium peroxide, BaO2, is formed. The next O has another two dots above and another two below.