NaOH is the limiting reactant
Given
12 g of sulfur reacts with 18 g of oxygen and 24 g of sodium hydroxide
Required
The limiting reactant
Solution
Reaction
2 S(s) + 3 O₂(g) + 4 NaOH(aq) ⇒ 2 Na₂SO₄(aq) + 2 H₂O(l)
[tex]\tt \dfrac{12}{32.065}=0.374[/tex]
[tex]\tt \dfrac{18}{32}=0.5625[/tex]
[tex]\tt \dfrac{24}{40}=0.6[/tex]
A method that can be used to find limiting reactants is to divide the number of moles of known substances by their respective coefficients, and the smallest ratio becomes a limiting reactant
S : O₂ : NaOH =
[tex]\tt \dfrac{0.374}{2}\div \dfrac{0.5625}{3}\div \dfrac{0.6}{4}=0.187\div 0.1875\div 0.15\Rightarrow NaOH~smallest~ratio[/tex]