Question

2C3H8O + 9O2 = 6CO2 + 8H2O   

How many grams of oxygen are needed to react with 26.4 mL of C2H8O? (d= 786 Kg/m^3)

Answer 1

density = 786 kg/m^3

This is same as:

density = 0.786 g/mL

now calculate mass of C2H8O using:

mass = density * volume

= 0.786 g/mL * 26.4 mL

= 20.75 g

mass of C3H8O = 20.75 g

molar mass of C3H8O = 60.094 g/mol

mol of C3H8O = (mass)/(molar mass)

= 20.75/60.094

= 0.3453 mol

Balanced chemical equation is:

2C3H8O + 9O2 = 6CO2 + 8H2O

According to balanced equation

mol of O2 required = (9/2)* moles of C3H8O

= (9/2)*0.3453

= 1.5538 mol

mass of O2 = number of mol * molar mass

= 1.5538*32

= 49.7 g

Answer: 49.7 g