Question

Determine the mass of oxygen that is needed to react with 33 grams of phosphorus.

4P + 5 O2 → 2 P205
A
27.3 grams O2
B
1.33 grams O2
С
213 grams 02
D
42.6 grams 02

Answer 1

D = 42.6 g

Step-by-step explanation:

Given data:

Mass of oxygen needed = ?

Mass of phosphorus react = 33 g

Solution:

Chemical equation:

4P + 5O₂ → 2P₂O₅

Number of moles of phosphorus:

Number of moles = mass/molar mass

Number of moles = 33 g/ 30.97 g/mol

Number of moles = 1.065 mol

now we will compare the moles of P and oxygen.

P : O₂

4 : 5

1.065 : 5/4×1.065 = 1.33mol

Mass of oxygen needed:

Mass = number of moles × molar mass

Mass = 1.33 mol × 32 g/mol

Mass = 42.6 g