Question

Suppose 5.25 mol of each reactant are used for the following chemical reactions, identify the limiting reactant. Explain.
____ C6H6 (l) + ____ O2 (s) → _____CO2 (g) + _____ H2O (g)

_____ Al (s) + + ____ Cl2 (s) → _____AlCl3 (s)

____ H2S (g) + ____ O2 (s) → _____SO2 (g) + _____ H2O (l)

Answer 1

1) Reaction given is not balanced reaction first balance it.

2 C ₆ H _{6 (l)} + 15 O _{2 ( s)} 12 CO _{2 (g)} + 6 H ₂ O _(g)

from reaction stoichiometric ratio of reactants = moles of benzene :moles of O ₂

= 2: 15

= 1 : 7.5

provided stoichiometric ratio of benzene : O ₂ := 5.25 : 5.25

From this it is clear that O ₂ is limiting reactant .

2) Reaction given is not balanced reaction first balance it.

2 Al _(s) + 3 Cl _{2 ( s)} 2 Al Cl _{3 (s)}

from reaction stoichiometric ratio of reactants = moles of Al: moles of Cl ₂

= 2: 3

= 1: 1.5

provided stoichiometric ratio of Al : Cl ₂ = 5.25 : 5.25 = 1 : 1

From this it is clear that Cl ₂ is limiting reactant .

3) Reaction given is not balanced reaction first balance it.

2 H ₂ S (g) + 3 O _{2( s)} 2 SO _{2 (g)} + 2 H ₂ O _(l)

from reaction stoichiometric ratio of reactants = moles of H ₂ S : moles of O ₂

= 2: 3

= 1: 1.5

provided stoichiometric ratio of H ₂ S : O ₂= 5.25 : 5.25 = 1 : 1

From this it is clear that O ₂ is limiting reactant .