"A car running on lead-free petrol is fitted with a catalytic converter to its exhaust system. An investigation shows that its exhaust gases contain small amounts of nitrogen oxides. Which modifications would lower the concentration of nitrogen oxides in the exhaust gases?"

1 of the option does not lower the concentration of oxide, rather it alters the rate of flow of exhaust
2 of the options alter the temperature, which does not make sense since catalytic converters only work at fairly high temperatures...

"In the catalytic converter on the exhaust system of a car, harmful gases are converted into carbon dioxide, nitrogen and water vapour. Which substance, present in car exhaust, can react with nitrogen monoxide, also in the fumes, to form non-poisonous products?"

Answer found here: http://www.chemguide.co.uk/physical/catalysis/introduction.html

"In which of the following chemical reactions does the transition metal or its compound behave as a heterogeneous catalyst?"

Remember in heterogeneous catalysis, the catalyst and the reactants are in different phases.

"The action of a heterogeneous catalyst may be explained in terms of"

This one is like duh

"What are the two main types of structure used in catalytic converters?"

wth is waffle and corrugated?

"Which gas is present in the exhaust fumes of a car engine in a much greater amount than any other gas?"

Answer found here: http://www.fordscorpio.co.uk/cats.htm


have fun learning!