Question

The concept of determining which reactant is limiting and which is in excess is akin to determining the number of sandwiches that can be made from a set number of ingredients. Assuming that a cheese sandwich consists of 2 slices of bread and 3 slices of cheese, determine the number of whole cheese sandwiches that can be prepared from 52 slices of bread and 69 slices of cheese.

Answer 1

2 slices of bread + 3 slices of cheese   -------------------> 1 cheese sandwich

            2                          3                                                           1

          52                        69                                                          ??

here

2 slices of bread need ----------------> 3 slices of cheese

52 slices of bread need ------------->        ??

slices of cheese = 52 x 3 / 2 = 78

so we need 78 slices of cheese . but we have only 69 slices of cheese.

so here limiting reagent is slices of cheese

3 slices of cheese   -------------------> 1 cheese sandwich

           3                                                           1

          69                                                          ??

cheese sandwich = 69 x 1 / 3 = 23

number of whole cheese sandwiches = 23