Acetylene gas (C2H2) is used in welding torches. When it reacts with oxygen, it produces carbon dioxide (CO2) and steam (H20). The reaction can be described by the equation 2C2H2+
502 —> 4CO2 + 2H20. How much mass of C2H2 is needed to produce 75.0 grams of CO2?

Mass C₂H₂ needed : 22.165 g

Reaction

2C₂H₂+ 5O₂ ⇒ 4CO₂ + 2H₂O

75.0 grams of CO₂ , mol CO₂ (MW=44 g/mol) :

mol C₂H₂ :

mass C₂H₂ (MW=26 g/mol) :

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

fe 55.85 g/mol and h2o 18.02 g/mol.