Look at the following hypothetical reaction: a+3b--> c+3d assume that the equation is balanced. in which of the following reactant mole ratios will reactant b be the limiting reagent? a) a: 4b b) a: 5b c) 2a: 7b d) a: b

d) A:B

Explanation: Limiting reagent is the reagent which limits the formation of products.

Excess reagent is the reagent which is present in excess in the reaction.

a) A:4B

As seen from the given equation, 1 mole of A reacts with 3 moles of B, thus (4-3)= 1 mole of B will remain and thus A is the limiting reagent and B is the excess reagent.

b) A:5B

As seen from the given equation, 1 mole of A reacts with 3 moles of B, thus (5-3)= 2 moles of B will remain and thus A is the limiting reagent and B is the excess reagent.

c) 2A:7B

As seen from the given equation, 1 mole of A reacts with 3 moles of B, thus 2 moles of A will react with 6 moles of B. Thus (7-6)= 1 mole of B will remain and is the excess reagent.

d) A: B

As seen from the given equation, 3 moles of B react with 1 mole of A, thus 1 mole of B will react with 0.33 moles of A and (1 - 0.33) =0.66 moles of A will remain as excess reagent. B is the limiting reagent.

a non redox reaction occurs when there is not a transfer of electrons. for redox reactions, which are reduction-oxidation reactions, a change in the oxidation number occurs. elements that are reduced gain electrons, and elements that are oxidized lose electrons.

explanation:

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.