Phosphorus is burned in air at 500 ºC to produce gaseous phosphorus(V) oxide. 220 g of phosphorus was reacted with an excess of air. Calculate the volume, in m3, of gaseous phosphorus(V) oxide produced

Additional information given:

P_{4 (s)} + 5O_{2  (g)} = P₄O_{10 (g)}     Pressure = 101kPa     Temp = 500^oC     gas constant R = 8.31JK^-1mol^-1

Question to student: What are the first observations from the equation? 

Equation is perfectly balanced; therefore it can be assumed that all the phosphorous has reacted, esp as there is an excess. The product is a gas of oxygen.

Question to student: With a highlighter, let's go through the question, identify the key information and what it means.From the information given, what equation can we use to calculate the volume?

Based on the information, we can use the ideal gas law to calculate the volume! PV = nRT... rearranged to V = nRT/P

n = no. of moles of phosporous in the reaction. We know that the atomic mass for the phosphorous element is 31gmol^-1. So the number of moles of P₄ in 220g would be 220 / (4 x 31) = 1.77

R = gas constant = 8.31 JK^-1mol^-1   

T= temp in Kelvin = 500^oC + 273 = 773K

P = gas pressure in Pa = 101 kPa x 1000

So, V = (1.77 x 8.31 x 773) / (101 x 1000) = 0.1128m³..... 0.113m³