If 84.1 g of NaOH and 51.0 g of Al and 25.0 g H20 react which chemical is the limiting reactant?

Explanation:

1. Chemical quation

The reaction of aluminium, sodium hydroxide and water is represented by the balanced chemical equation:

The coefficients of each reactant and product give the theoretical mole ratios.

To find the limiting reactant you compare the theoretical ratios with the ratio of the available substaces.

2. Theoretical mole ratio:

Equivalent to

3. Actual ratio

a) Convert each mass to number of moles

Formula:

Al:

NaOH:

H₂O:

Divide all the mole amounts by the least number:

4. Comparison

Theoretical ratio:

Actual ratio:

     Multiply by 3:

Now, yo can see that the first two are in excess with respect the third one, making that the water consumes first, before any of the other two consumes. Therefore, the limiting reactant is the water.

law of conservation of matter