Name the pollutant with the lowest concentration in 2019.
Name the pollutant whose concentration shows a continuous decrease from 2019 to 2022.
Calculate the average mass, in ng, of sulfur dioxide in a 250 cm$^3$ sample of polluted air in 2020.
State one source of sulfur dioxide in the atmosphere.
State one adverse effect of sulfur dioxide in the atmosphere.
Choose the compound used to remove sulfur dioxide in flue gas desulfurisation. Tick ($\checkmark$) one box. aluminium chloride calcium oxide methane sulfuric acid
Complete the symbol equation for this reaction. $\text{Na}_2\text{SO}_3 + \ldots\text{HCl} \rightarrow 2\text{NaCl} + \text{SO}_2 + \ldots$
Name the acidified solution used to test for sulfur dioxide gas and state the observations.
Give the formula of the ion present in all alkaline solutions.
Choose from the list the pH value for an alkaline solution. Draw a circle around your selected answer. pH1 pH4 pH7 pH13