Consider the equation $3 \mathrm{A}+\mathrm{B} \rightarrow \mathrm{C}+\mathrm{D} .\( You react 4 moles of A with 2 moles of \)\mathrm{B}$ . Which of the following is true? a. The limiting reactant is the one with the higher molar mass. b. A is the limiting reactant because you need 6 moles of A and have 4 moles. c. B is the limiting reactant because you have fewer moles of B than A. d. B is the limiting reactant because three A molecules react with each B molecule. e. Neither reactant is limiting. Justify your choice. For those you did not choose, explain why they are incorrect.

The balanced equation is given as: \(3A + B \rightarrow C + D\) We are given 4 moles of A and 2 moles of B.

In this balanced equation, the stoichiometric ratio of A to B is 3:1, meaning that for each mole of B, there must be 3 moles of A present for the reaction to go to completion.

The actual ratio of A:B is given by the moles of A divided by the moles of B. In this case, it is given as: \(\frac{4\,\text{moles of A}}{2\,\text{moles of B}} = 2:1\)

We can see that the stoichiometric ratio (3:1) is greater than the actual ratio (2:1). This indicates that there is not enough A available to react with all the B present. Therefore, A is the limiting reactant. B is not the limiting reactant since there are enough moles of B to react with all the moles of A present.

a. The limiting reactant is the one with the higher molar mass. This statement is incorrect because the limiting reactant is determined by comparing the stoichiometric ratio and the actual ratio, not by comparing molar masses. b. A is the limiting reactant because you need 6 moles of A and have 4 moles. This statement is correct because the stoichiometric ratio of A to B is 3:1, and there are not enough moles of A to react with all the moles of B present. c. B is the limiting reactant because you have fewer moles of B than A. This statement is incorrect because the limiting reactant is determined by comparing the stoichiometric ratio and the actual ratio, not by the amounts of moles present. d. B is the limiting reactant because three A molecules react with each B molecule. This statement is incorrect because although the stoichiometric ratio is 3:1, the actual ratio favors A and there is not enough A present to react with all the B present. e. Neither reactant is limiting. This statement is incorrect because the actual ratio (2:1) does not match the stoichiometric ratio (3:1), indicating that one of the reactants is limiting. Thus, the correct choice is (b). A is the limiting reactant because you need 6 moles of A and have 4 moles.