Question

How many liters of excess reactant would be left when 3.00 liters of nitrogen monoxide is mixed with 2.00 liters of oxygen and allowed to react at 695 torr and 27 degrees Celsius to produce nitrogen dioxide

Answer 1

Start from the equation

2NO + O2 => 2NO2

so 2 moles + 1 mole gives 2 moles

or

2 volumes + 1 volume gives 2 volumes

Now decide which of the starting materials in excess

Answer 2

NO