Question

When FeC13 is ignited in an atmosphere of pure oxygen, this reaction takes place. 4FeCl3(sJ 30lgJ ~ 2F~0 (sJ 6Cl2(gJ If 3.00 mol of FeC13 are ignited in the presence of 2.00 mol of 0 2 gas, how much of which reagent is present in excess and therefore remains unreacted

Answer 1

Answer : The reagent present in excess and remains unreacted is,
`O_2`

Solution : Given,

Moles of
`FeCl_3` = 3.00 mole

Moles of
`O_2` = 2.00 mole

Excess reagent : It is defined as the reactants not completely used up in the reaction.

Limiting reagent : It is defined as the reactants completely used up in the reaction.

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

`2FeCl_3(s)+O_2(g)\rightarrow 2FeO(s)+3Cl_2(g)`

From the balanced reaction we conclude that

As, 2 moles of
`FeCl_3` react with 1 mole of
`O_2`

So, 3.00 moles of
`FeCl_3` react with
`(3.00)/(2)=1.5` moles of
`O_2`

From this we conclude that,
`O_2` is an excess reagent because the given moles are greater than the required moles and
`FeCl_3` is a limiting reagent and it limits the formation of product.

Hence, the reagent present in excess and remains unreacted is,
`O_2`