A mixture of nitrogen monoxide and oxygen reacts in a closed vessel of volume V V\,V at temperature T T\,T according to the equation:
2NO(g)+O2(g)→2NO2(g) 2\text{NO}(\text{g}) + \text{O}_2(\text{g}) \rightarrow 2\text{NO}_2(\text{g}) 2NO(g)+O2(g)→2NO2(g)Which of the following changes to the reaction conditions will decrease the rate of this reaction?
Adding a fixed mass of helium gas to the vessel while keeping the volume VVV and temperature TTT constant.
Increasing the volume of the reaction vessel to 2V2V2V at constant temperature TTT.
Increasing the temperature of the vessel from TTT to T+20 KT + 20\text{ K}T+20 K at constant volume VVV.
Introducing a finely divided platinum catalyst into the vessel.
