Wunna S.5 Biology Items 68De8E9B396914.91052074

KIBUGO 1 CHEMISTRY DEPARTMENT 2024 S.5 BRAINSTORMING TEST ONE TOPIC ; MATTER AND IT’S PARTICULATE NATURE SUBTOPIC; DIFFUSION AND MASS SPECTROMETER NAME…………………………………………………………………………… ………..COMBN……………….. INSTRUCTIONS Attempt all questions in this paper. 1. (a) Define the following terms (i) Relative Atomic Mass. (01 mark) …………………………………………………………………………………………………………………………………………......... ................................................................................................................... .................................... (ii) Relative abundance (01 mark) …………………………………………………………………………………………………………………………………………......... ............................................................................................................................. .......................... (iii) isotopes (01 mark) …………………………………………………………………………………………………………………………………………......... .............. ............................................................................................................................. ............ (b) Copper, relative atomic mass of 63.5 has two isotopes of mass numbers 6 3 and 65. Calculate the percentage abundance of each isotope of copper. (1½ marks) …………………………………………………………………………………………………………………………………………......... …………………………………………………………………………………………………………………………………………......... …………………………………………………………………………………………………………………………………………......... KIBUGO 2 (c) Draw the mass spectrum of the above copper sample . (1½ marks) (d) State one use of a mass spectrometer to a chemist. (1½ marks) …………………………………………………………………………………………………………………………………………......... ............................................................................................................................. .......................... 2. (a) A mass spectrum of chlorine shows molecular peaks at 70, 72 and 74. Explain this observation. (02 marks) …………………………………………………………………………………………………………………………………………......... ............................................................................................................................. .......................... ………………………………………………………………………………………………………………………………………………… …………………………………………………………… …………………………………………………………… …………………… ……………………………………………………………………… ………………………… ………………………………………......... ................................................................ .......... ............................................................................. KIBUGO 3 (b) Chlorine has two isotope s Cl-35 and Cl-37. State the formula of each ion of the respective molecular peak formed. (1 ½ marks) Molecular peak Formula of the ion 70 72 74 (c) State one advantage and one disadvantage of determining the relative atomic mass of an element using the mass spectrum Advantage (0½ mark) …………………………………………………………………………………………………………………………………………......... Disadvantage (0½ mark) ........................................................................................................................ ............................... (d) State two methods that may be used to obtain ions in the mass spectrometer. (01 mark) ……………………………………………………………………… ………………………… ………………………………………......... ................................................................ .......... .............................................. ........................ ....... e) What property of the ions does the mass spectrometer measure? (01 mark) ……………………………………………………………………… ………………………… ………………………………………......... KIBUGO 4 3. The table below shows the information from a mass spectrum sample Isotope Detector current (mA) 204 0.16 206 2.72 207 2.50 208 5.92 Calculate (i) the relative abundance of the different isotopes of lead in the …