Chemistry 0620 · IGCSE · Identification of ions and gases

Identification of ions and gases — practice question

The table gives the masses of several ions in a 1000 cm$^3$ toothpaste sample.
(a(i))[1]

State which negative ion has the greatest mass in 1000 cm$^3$ of toothpaste.

(a(ii))[1]

Name the compound that has NH$_4^+$ ions and CO$_3^{2-}$ ions.

(a(iii))[1]

Calculate the mass of fluoride ions in 250 cm$^3$ of toothpaste.

(b)[2]

Describe what is seen when aqueous ammonia is added a little at a time to a solution containing zinc ions until the ammonia is in excess. observations with a few drops of ammonia observations with ammonia in excess

(c)[1]

Deduce the formula of compound A so that it shows the numbers of carbon, hydrogen and oxygen atoms.

(d(i))[2]

Complete these sentences about ethanol using words from the list. different formula group identical molecule similar Every member of the alcohol homologous series has the same functional ................. . Members of the same homologous series have chemical properties that are ................. .

(d(ii))[2]

When ethanol undergoes incomplete combustion, a small amount of carbon dioxide is produced. Name two other substances that are formed when ethanol undergoes incomplete combustion.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: the phosphate ion, PO₄^{3}⁻

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