Chemistry 0620 · IGCSE · Air quality and climate

Air quality and climate — practice question

Ar, CO$_2$, N$_2$ and O$_2$ are the gases present in clean, dry air. By contrast, polluted air commonly contains CO, NO, NO$_2$ and SO$_2$.
(a)[1]

To the nearest whole number, what percentage of clean, dry air is N$_2$?

(b)[2]

Name the process by which O$_2$ is separated from clean, dry air.

(c)[1]

State one important harmful effect of the pollutant SO$_2$.

(d)[2]

Describe the way oxides of nitrogen are formed in a car engine.

(e)[3]

Identify these products and state which metal catalyst is used.

(f)[2]

Write a chemical equation that shows the incomplete combustion of methane.

(g(i))[2]

State the scientific names for process A and process B.

(g(ii))[2]

Complete the diagram so that it shows the complex carbohydrate made from three glucose units. Include all of the atoms and all of the bonds in the linkages.

(g(iii))[2]

State two methods by which complex carbohydrates can be broken down into simple sugars.

(g(iv))[1]

Name one suitable technique for separating and identifying the individual sugars produced when complex carbohydrates are broken down.

Worked solution & mark scheme

This 18-mark question has a full step-by-step worked solution and mark scheme. One marking point: 78%

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI