A mixture of C3H8 and C2H2 has a mass of 2.0g . It is burned in excess O2 to form a mixture of water and carbon dioxide that contains 1.6 times as many moles of CO2 as of water.
Find the mass of C2H2 in the original mixture.
To find the mass of C2H2 in the original mixture, we will follow these steps:
1. Determine the number of moles of CO2 and water produced in the combustion reaction by using stoichiometry.
2. Find the number of moles of C2H2 in the original mixture using the mole ratios from the balanced equation.
3. Calculate the mass of C2H2 using its molar mass.
Let's start by balancing the combustion equation for the reaction between C3H8 and O2:
C3H8 + O2 -> CO2 + H2O
Based on the information provided, we know that 1 mole of C2H2 produces 2 moles of CO2 and that the number of moles of CO2 is 1.6 times the number of moles of water formed.
Using this information, we can set up the following mole ratio:
2 moles of CO2 : 1 mole of water : 1 mole of C2H2
Step 1: Determine the moles of CO2 and water formed
Since we know that the number of moles of CO2 is 1.6 times the number of moles of water, let's assume "x" represents the number of moles of water. Therefore, the number of moles of CO2 will be 1.6x.
Since we have the mass of the mixture and we want to find the mass of C2H2, we don't need to calculate the actual number of moles. We can use the mole ratios to find the mass directly.
Step 2: Calculate the mass of C2H2
The molar mass of C2H2 can be found by adding the molar masses of carbon (C) and hydrogen (H):
Molar mass of C2H2 = (2 * molar mass of C) + (2 * molar mass of H)
Now that we have the molar mass of C2H2, we can calculate the mass of C2H2 using the mole ratio between C2H2 and CO2:
Mass of C2H2 = (Moles of C2H2) * (Molar mass of C2H2)
With these steps, we can find the mass of C2H2 in the original mixture.