Question

Carlos is making phosphorous trichloride using the equation below. He adds 15 g of phosphorus.

2P +3Cl2 → 2PCl3

How much chlorine would be found in the product?

5 g
7.5 g
45 g
90 g

Answer 1

Answer C "45g"

Multiply 2*7.5=15 then 15*3=45

Answer 2

m = 45 g

Step-by-step explanation:

mass of phosphorus added to the reaction is

m = 15 g

atomic mass of phosphorus atom is given as

W = 31 g/mol

now number of moles of phosphorus atom is given as

`n = (mass)/(molar mass)`

`n = (15)/(31)`

now as we can see the reaction the number of moles of phosphorus and the number of moles of the product formed must be same

So here moles of the product formed must be

`n_(product) = (15)/(31)`

molar mass of chlorine in the product is given as

`W = 3(35.5) = 106.5 g/mol`

now the mass of the chlorine in product formed is given as

`m = moles * molar mass`

`m = (15)/(31) * 106.5 = 51.5 g`

so its nearly 45 g