Barium azide (Ba(N3)2\text{Ba(N}_3)_2Ba(N3)2) is an inorganic compound that decomposes upon heating to yield barium metal and nitrogen gas. The chemical equation for this thermal decomposition is:
Ba(N3)2(s)→Ba(s)+3N2(g) \text{Ba(N}_3)_2(\text{s}) \rightarrow \text{Ba}(\text{s}) + 3\text{N}_2(\text{g}) Ba(N3)2(s)→Ba(s)+3N2(g)Barium azide is utilized in certain specialized rapid-inflation gas generators to generate nitrogen gas swiftly.
A certain gas bag has a total volume of 108 dm3108\text{ dm}^3108 dm3 when fully inflated. Calculate the amount of nitrogen gas, in moles, required to fill this bag. (Assume that the molar volume of a gas under these operating conditions is 24 dm3 mol−124\text{ dm}^3\text{ mol}^{-1}24 dm3 mol−1.)
Using your answer to (a)(i), calculate the mass, in grams, of barium azide required to generate 108 dm3108\text{ dm}^3108 dm3 of nitrogen gas. [Relative atomic masses: Ba=137\text{Ba} = 137Ba=137, N=14\text{N} = 14N=14]
The gas generator is also packed with iron(III) oxide (Fe2O3\text{Fe}_2\text{O}_3Fe2O3). This reagent reacts with the highly reactive barium metal produced during the decomposition. The chemical equation for this process is:
3Ba(s)+Fe2O3(s)→3BaO(s)+2Fe(s) 3\text{Ba}(\text{s}) + \text{Fe}_2\text{O}_3(\text{s}) \rightarrow 3\text{BaO}(\text{s}) + 2\text{Fe}(\text{s}) 3Ba(s)+Fe2O3(s)→3BaO(s)+2Fe(s)State one reason why it is desirable for the designers of the gas generator to include this secondary reaction.
In addition, the generator contains silicon dioxide (SiO2\text{SiO}_2SiO2), which reacts with the barium oxide (BaO\text{BaO}BaO) produced in the reaction above to form a stable, glassy barium silicate (BaSiO3\text{BaSiO}_3BaSiO3) solid that safely immobilizes the residues. Construct a balanced chemical equation, including state symbols, for the formation of barium silicate from barium oxide and silicon dioxide.
Azides can also be reacted to produce lead(II) azide (Pb(N3)2\text{Pb(N}_3)_2Pb(N3)2), which is widely used as an initiator in detonators:
Pb(NO3)2(aq)+2NaN3(aq)→Pb(N3)2(s)+2NaNO3(aq) \text{Pb(NO}_3)_2(\text{aq}) + 2\text{NaN}_3(\text{aq}) \rightarrow \text{Pb(N}_3)_2(\text{s}) + 2\text{NaNO}_3(\text{aq}) Pb(NO3)2(aq)+2NaN3(aq)→Pb(N3)2(s)+2NaNO3(aq)What class of chemical reaction is represented by this equation?
Identify the laboratory method that should be employed to separate the solid lead(II) azide from the liquid mixture.
80 exam-style questions on Edexcel IGCSE Chemistry Chemical formulae, equations and calculations. Each one has a worked solution and a mark scheme showing where the marks go.