Answer:
Ammonia (NH3) molecules effuse 1.28 times faster than carbon monoxide (CO) molecules.
Explanation:
The kinetic molecular theory tells us that
Vrms = √(3RT/MW) where Vrms is the root mean square velocity of an ideal gas. So Vrms is inversely proportional to MW and so will be the rate of effusion.
Comparing NH3 and CO we have:
rate(NH3)/rate(CO) = √MW(CO)/√MW(NH3) = √28.01/√17.03 = 1.28
rate(NH3) = 1.28 x rate(CO)