Question

How many moles of pcl5 can be produced from 57.0 g of cl2 (and excess p4)?

Answer 1

Answer : The number of moles of
`PCl_5` produced can be 0.321 moles.

Solution : Given,

Mass of
`Cl_2` = 57.0 g

Molar mass of
`Cl_2` = 71 g/mole

First we have to calculate the moles of
`Cl_2`.

`\text{ Moles of }Cl_2=\frac{\text{ Mass of }Cl_2}{\text{ Molar mass of }Cl_2}=(57.0g)/(71g/mole)=0.803moles`

Now we have to calculate the moles of
`PCl_5`

The balanced chemical reaction is,

`P_4+10Cl_2\rightarrow 4PCl_5`

From the reaction, we conclude that

As, 10 mole of
`Cl_2` react to give 4 mole of
`PCl_5`

So, 0.803 moles of
`Cl_2` react to give
`(0.803)/(10)* 4=0.321` moles of
`PCl_5`

Therefore, the number of moles of
`PCl_5` produced can be 0.321 moles.

Answer 2

The reaction will take place according to the equation;
P4 + 10Cl2 = 4PCl5
1 mole of Cl2 contains 70.9 g/mol
Therefore, the number of moles of Cl2 will be;
= 57 g/ 70.9 g/mol
= 0.804 moles
The mole ratio of Cl2 : PCl5 = 10:4
Therefore; the number of moles of PCl5 = (0.804/10)×4
= 0.3216 moles