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Miracle Learning Centre Chemistry Tuition Question on Mole Concept. (O Level / IP Chemistry)

1) Air-bags are used to protect drivers from injury during an accident. They contain the school sodium azide, NaN3, which decomposes rapidly to form sodium and nitrogen. The nitrogen formed fills the air-bag. (a) Construct the equation for the decomposition of sodium azide. _________________________________________________________ [1]
(b) In a crash, an air-bag fills with 144 dm3 of nitrogen at room temperature and pressure. What mass of sodium azide is needed to provide the nitrogen? [2]
(c) Sodium azide reacts with dilute hydrochloric acid to give sodium chloride and a compound Y. Compound Y contains 2.33% hydrogen and 97% nitrogen by mass. (i) What is the empirical formula for Y? [2] (ii) What other information is required in order to find the molecular formula of Y? _________________________________________________________ [1]
Miracle Learning Centre Answer to Chemistry Tuition Question on Mole Concept. (O Level / IP Chemistry) 1(a) 2NaN3  2 Na + 3 N2 Mr NaN3 = 65 Mass of NaN3 = x 2 x 65 = 260 g (i) N : H = 97.7 / 14 : 2.33 / 1 = 3 : 1 The empirical formula is N3H (ii) The molecular mass of Y Learn from our Chemistry Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Chemistry tuition, Physics tuition, Maths tuition and Science tuition Classes.