Question

HCl + NaOH → NaCl + H2O If 30 g of HCl is combined with 20 g of NaOH, which is the limiting reactant?

Answer 1

Molar mass of NaOH is 39.997g, while molar mass of HCl is 36.46g, so, with equal coefficients in equation, and less NaOH to start out with, it is clear that NaOH is the limiting reactant here.

Answer 2

Answer : The limiting reagent is, NaOH

Explanation : Given,

Mass of HCl = 30 g

Mass of NaOH = 20 g

Molar mass of HCl = 36.5 g/mole

Molar mass of NaOH = 40 g/mole

First we have to calculate the moles of $HCl$ and $NaOH$.

$\text{Moles of }HCl=\frac{\text{Mass of }HCl}{\text{Molar mass of }HCl}=\frac{30g}{36.5g/mole}=0.82moles$

$\text{Moles of }NaOH=\frac{\text{Mass of }NaOH}{\text{Molar mass of }NaOH}=\frac{20g}{40g/mole}=0.5moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that

As, 1 mole of $HCl$ react with 1 mole of $NaOH$

So, 0.82 moles of $HCl$ react with 0.82 moles of $NaOH$

That means, in the given balanced reaction, $NaOH$ is a limiting reagent because it limits the formation of products and $HCl$ is an excess reagent.

Hence, the limiting reagent is NaOH