The table shows the recipe and the available ingredients for making the maximum possible number of sandwiches. Making Sandwiches

Recipe for One Sandwich:
2 cheese slices, 1 ham slice, 2 bread slices

Ingredients Available:
12 cheese slices, 10 ham slices, 12 bread slices
If the ingredients represent reactants of a chemical reaction, which of the following represents the leftover reactant?

A. 2 ham slices

B. 4 ham slices

C. 2 cheese slices

D. 4 cheese slices

B. 4 ham slices

Explanation:

A chemical reaction involves one or more substances known as reactants combining chemically to give one or more substances known as products.

Reactants in chemical reactions combine in definite mole or mass ratios to give products. Therefore, when one substance is present in excess of what is required to combine with another to form products, that substance is known as the excess reagent. The other substance which is present in a smaller amount and which when used up, the reaction stops is known as the limiting reagent.

From the illustration of the sandwiches in the question, the recipe for one sandwich represents the chemical equation of a reaction. The equation form is given below:

2 cheese slices + 1 ham slice + 2 bread slices ---> 1 sandwich

The ratio of the reactant is 2 : 1 : 2

From the available ingredients, 12 cheese slices, 10 ham slices, 12 bread slices.

12 cheese slices will require 6 ham slices and 12 bread slices to produce 6 sandwiches.

However, since there are 10 ham slices, 4 ham slices will be left over unused. This is the excess or leftover reactant.