Which of the following involves combination of two elements ?
(a) N2(g) + 3H2(g) → 2NH3(g)
(b) CaO(s) + CO2(g) → CaCO3(g)
(c) 2SO2(g) + O2(g) → 2SO3f(g)
(d) NH3(g) + HCl(g) → NH4Cl(s)
Which of the following involves combination of two elements ?
(a) N2(g) + 3H2(g) → 2NH3(g)
(b) CaO(s) + CO2(g) → CaCO3(g)
(c) 2SO2(g) + O2(g) → 2SO3f(g)
(d) NH3(g) + HCl(g) → NH4Cl(s)










