1) Chemical equation:
2CO + O2 ---> 2CO2
2) molar ratios 2 moles CO : 1 mol O2 : 2 moles CO2.
3) When temperature and pressure is kept constant, the molar ratios are equal to the volume ratios.
So, at the same temperature and pressure conditions (standard) you ca state
2 L CO : 1 LO2 : 2 L CO2
=> 2L CO : 2 L CO2 => 1L CO : 1 L CO2.
So, 1 liter of CO2 is produced when 1 liter of CO reacts with excess O2.
Feeling ice melt on your skin
They're not important when solving math problems in class because you need to get the correct and accurate answers hence don't need to change them into significant figures
It would be 6 because of the elements