Question

In a reaction x + y + z₂ → xyz₂ identify the Limiting reagent if any, in the following reaction mixtures.
(a) 200 atoms of x + 200 atoms of y + 50 molecules of z₂
(b) 1 mol of x + 1 mol of y+3 mol of z₂
(c) 50 atoms of x + 25 atoms of y+50 molecules of z₂
d) 2.5 mol of x +5 mol of y+5 mol of z₂

Answer 1

According to the Reaction,  1 mole of x reacts with 1 mole of y and 1 mole of z. 
⇒ Also, 1 atom of x reacts with 1 atoms of y and 1 molecules of the z. 


(a). 1 atom of x reacts with 1 atom of y and 1 molecules of z. 
∴ 200 atoms of x reacts with 200 atoms of y and 200 molecules of x. 
In this, Molecules of the z required is greater than the molecules of the z present. Hence, z is the limiting reactant and x and y is in the excess. 

(b). 1 mole of the x reacts with 1 mole of y and 1 mol of z.
In this, number of the moles of the y are present in the high amount as required by the Reaction, hence it is the Excess reagent. 
∴ x and y is the limiting reagent in the reaction. 

(c). 1 atoms of x reacts with the 1 atoms of y and 1 molecules of the z. 
∴ 50 atoms of the x reacts with the 50 atoms of the y and 50 molecules of the z. 
In this, numbers of the atoms of y required is greater than what is present.
∴ y is the limiting reagent.

(d). 1 mol of the x reacts with 1 mol of y and 1 mole of the z.
∴ 5 mol of x reacts with the 5 mol of y and 5 mol of the z. 
In this, numbers of the moles of the x required is greater than what is present, therefore x is the limiting reactant or reagent. 



Hope it helps.

Answer 2

Answer:

(a)Z

(b)x and y

(c)y

(d)x