The presence of which of the following is the best indicator of incomplete combustion of petrol or diesel in an automobile engine?

The incorrect statement$(s)$ among $(a) - (d)$ regarding acid rain is (are) :
$(a)$ It can corrode water pipes.
$(b)$ It can damage structures made up of stone.
$(c)$ It cannot cause respiratory ailments in animals.
$(d)$ It is not harmful for trees.

How many ozone molecules are destroyed by a single chlorine free radical?

Which among the following statements is $NOT$ a principle of green chemistry?

Assertion : Suspended particulate matter $(SPM)$ is an important pollutant released by diesel vehicles.
Reason : Catalytic converters greatly reduce pollution caused by automobiles.

Which of the following is not a greenhouse gas?