If you mix NaOH and HCl, both having 45.0mL of volume, which of the two is the limiting reactant?

Question

Wyatt Adkins · Accepted Answer

You can't tell without knowing the molarities of the two solutions.

Sodium hydroxide, #"NaOH"#, a strong base, will react with hydrochloric acid, #"HCl"#, a strong acid, to form sodium chloride, #"NaCl"#, and water. This is how the neutralization reaction's balanced chemical equation looks. #"NaOH"_text((aq]) + "HCl"_text((aq]) -> "NaCl"_text((aq]) + "H"_2"O"_text((l])# Notice that you have a #1:1# mole ratio between sodium hydroxide and hydrochloric acid. This means that the reaction consumes equal numbers of moles of each reactant. You must know how many moles of each reactant you have in order to identify which of the two is a limiting reagent. The mole ratio becomes equal to a concentration ratio when two solutions of equal volumes are mixed, as in this case. You are aware that the molarity of a solution is described as #C = n/V" "#, where #n# - the number of moles of solute; #V# - the volume of the solution. If it were you, you would have #C_"HCl" = n_"HCl"/V " "# and #" "C_"NaOH" = n_"NaOH"/V# This is the same as #V = n_"HCl"/C_"HCl" implies n_"NaOH"/C_"NaOH" = n_"HCl"/C_"HCl"# The mole ratio of hydrochloric acid to sodium hydroxide is #n_"NaOH"/n_"HCl" = C_"NaOH"/C_"HCl"# The solution with the lower concentration will function as a limiting reagent because equal volumes of solutions with equal concentrations will have equal numbers of moles of each reactant. Thus, keep in mind that when you add equal volumes of each reactant, their individual molarities will dictate which reactant is excess and which acts as a limiting reagent.

Owen Ambrose · Answer

undefined To determine the limiting reactant, you need to compare the moles of each reactant. First, calculate the moles of NaOH and HCl using their respective molarities and volumes. Then, determine the mole ratio of NaOH to HCl in the balanced chemical equation. The reactant that produces fewer moles of product is the limiting reactant. Finally, compare the moles of product produced by each reactant to confirm which one is the limiting reactant.