Question

what is the maximum amount of moles of P2O5 that can theoretically be made from 136 g of P4 and excess oxygen

Answer 1

We are given with
136 g P4
excess oxygen

The complete combustion reaction is
P4 + 5O2 => 2P2O5
Converting the amount of P4 to moles
136/123.9 = 1.098 moles

Using stoichiometry
moles P2O5 = 1.098 x 2 = 2.195 moles P2O5

Answer 2

Answer: The maximum number of moles of
`P_2O_5` theoretically made is 2.194 moles.

Step-by-step explanation:

To calculate the number of moles, we use the equation

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}`

Given mass of
`P_4` = 136 g

Molar mass of
`P_4` = 123.9 g/mol

Putting values in above equation, we get:

`\text{Moles of }P_4=(136g)/(123.9g/mol)=1.097mol`

The chemical equation for the formation of
`P_2O_5` follows:

`P_4+5O_2\rightarrow 2P_2O_5`

Oxygen is present in excess, so it is considered as an excess reagent.

`P_4` is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

If 1 mole of
`P_4` is producing 2 moles of
`P_2O_5`

So, 1.097 moles of
`P_4` will produce =
`\frac{2}[1}* 1.097=2.194mol` of
`P_2O_5`

Hence, the maximum number of moles of
`P_2O_5` theoretically made is 2.194 moles.