Last question anyone please help

Question

What mass, in grams, of C₂H₂ is needed to form 157.9 g of CO₂? Assume excess oxygen.

 

 2C₂H₂(g) + 5O₂(g) → 4CO₂(g) + 2H₂O(g)

 

 × 10 click to select g C2H2

Answer 1

What mass, in grams, of C₂H₂ is needed to form 157.9 g of CO₂? Assume excess oxygen.

 

 2C₂H₂(g) + 5O₂(g) → 4CO₂(g) + 2H₂O(g)

grams CO2 to moles CO2 with molar mass

157.9/44.01=3.58782095 mol CO2

mol CO2 to mol C2H2 with coefficients:

3.58782095molCO2 (2molC2H2/4molCO2)=1.793910475 mol C2H2

mol to grams with molar mass:

1.793910475 mol C2H2 (26.038g/1mol)=46.70984 g C2H2

probably round to 4 sig figs,

46.70984

46.71 g C2H2