(a)[2]
Polluted water may include harmful substances such as plastics and phosphates. State two different kinds of harmful substance found in polluted water.
(b(i))[1]
Name the negative ion with the lowest concentration.
(b(ii))[1]
State the name of the $\text{NO}_3^-$ ion.
(b(iii))[1]
Calculate the mass of sodium ions contained in $250\text{ cm}^3$ of polluted water.
(c(i))[1]
Complete Fig. 3.1 by filling in the final stage.
(c(ii))[1]
State the reason carbon is added to drinking water.
(d)[2]
Describe how you would test the purity of water by using melting point.
(e)[2]
Complete the symbol equation for the reaction between phosphorus(V) chloride, $\text{PCl}_5$, and water. $2\text{PCl}_5 + 8\text{H}_2\text{O} \rightarrow \ldots\ldots\text{H}_3\text{PO}_4 + \ldots\ldots\text{HCl}$