A laboratory is comparing the following reactions for producing ammonia. Ammonia is the desired product in each process. (Relative atomic masses: H = 1, N = 14, O = 16, Na = 23, S = 32, Cl = 35.5, Ca = 40)
Process P: NH4Cl+NaOH→NH3+NaCl+H2O\mathrm{NH_{4}Cl + NaOH \rightarrow NH_{3} + NaCl + H_{2}O}NH4Cl+NaOH→NH3+NaCl+H2O
Process Q: (NH4)2SO4+2NaOH→2NH3+Na2SO4+2H2O\mathrm{(NH_{4})_{2}SO_{4} + 2NaOH \rightarrow 2NH_{3} + Na_{2}SO_{4} + 2H_{2}O}(NH4)2SO4+2NaOH→2NH3+Na2SO4+2H2O
Process R: 2NH4Cl+Ca(OH)2→2NH3+CaCl2+2H2O\mathrm{2NH_{4}Cl + Ca(OH)_{2} \rightarrow 2NH_{3} + CaCl_{2} + 2H_{2}O}2NH4Cl+Ca(OH)2→2NH3+CaCl2+2H2O
Which shows a sequence in which each process has a greater atom economy for ammonia than the process before it?
Process P, Process Q, Process R
Process Q, Process R, Process P
Process R, Process P, Process Q
Process Q, Process P, Process R
151 exam-style questions on Edexcel GCSE Chemistry 6.2 Quantitative analysis, covering 6.2.1 Concentration in mol dm⁻³ and titration calculations, 6.2.2 Percentage yield and why actual yield falls short, 6.2.3 Atom economy of a reaction, 6.2.4 Choosing a reaction pathway, and 6.2.5 Molar volume of gases and Avogadro's law. Each one has a worked solution and a mark scheme showing where the marks go.