(a(i))[2]
State two other substances in water that are harmful to aquatic life.
(a(ii))[1]
State why phosphates are harmful to aquatic life.
(b(i))[1]
Name the positive ion that has the greatest concentration.
(b(ii))[1]
State the name of the NO$_3^-$ ion.
(b(iii))[1]
Calculate the mass of magnesium ions in 250 cm$^3$ of polluted water.
(c(i))[1]
Describe how white copper(II) sulfate can be converted into blue copper(II) sulfate.
(c(ii))[1]
Select the word from the list that best describes white copper(II) sulfate: anhydrous, aqueous, hydrated, oxidised.
(d)[2]
Complete the symbol equation for the reaction of calcium with water. Ca + [BLANK]H$_2$O → Ca(OH)$_2$ + [BLANK]