Salicylic acid (c7h6o3) reacts with acetic anhydride (c4h6o3) to form acetylsalicylic acid (c9h8o4).

2c7h6o3(aq) + c4h6o3(aq) mc002-1.jpg 2c9h8o4(aq) + h2o(l)

what is the limiting reactant if 70.0 g of c7h6o3 and 80.0 g of c4h6o3 react?
a water
b salicylic acid
c acetic anhydride
d acetylsalicylic acid

Answer : The correct option is, (B) Salicylic acid

Solution :

First we have to calculate the moles of salicylic acid and acetic anhydride.

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

From the balanced reaction we conclude that

As, 2 moles of salicylic acid react with 1 mole of acetic anhydride

So, 0.507 moles of salicylic acid react with mole of acetic anhydride

The excess of acetic anhydride = 0.783 - 0.2535 = 0.5295 moles

That means the in the given balanced reaction, salicylic acid is a limiting reagent because it limits the formation of products and acetic anhydride is an excess reagent.

Hence, the limiting reagent is, salicylic acid.

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.