Acettlene gas (C2H2) is used in welding. During one job, a welder burns 48.0 g of acetylene. Using a balanced equation for the complete combustion of acetylene, calculate the following:

Question

Balanced Equation
a) the mass of oxygen used
b) the mass if carbon dioxide produced
c) the mass of water produced
Use your answers from. A) B) and C) to show that this equation obeys the law of conservation of mass

Answer 1

2C2H2 + 5O2 ==> 4CO2 + 2H2O

b. mols C2H2 burned = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols C2H2 to mols CO2.
Now convert mols CO2 to g CO2. g CO2 = mols CO2 x molar mass CO2 = ?

c is done the same way.

a is done the same way.

For the last part, grams on the left = grams on the right. Check that out to see if the law of conservation of mass is true.