The gas used in the manufacture of Vanaspati Ghee from Vanaspati Oil is –

The gas used to inflate the tyres of an aircraft is –

Which one of the following is the permanent gas in the atmosphere?

Which one of the following catalysts is used in hydrogenation of vegetable oils?

The gas used in discharge tubes for optical decoration and advertising is –

Which of the following pair of gases is used for the respiratory activities of divers?