How many grams of co2 are contained in 550 ml of the gas at stp?

V = 550 mL = 0.550 L
V = 22.4 L/mol   (STP)
M(CO₂)=44.01 g/mol

n(CO₂)=v/V

m(CO₂)=n(CO₂)M(CO₂)=vM(CO₂)/V

m(CO₂)=0.550*44.01/22.4=1.08 g