Chemistry 0620 · IGCSE · The mole and the Avogadro constant

The mole and the Avogadro constant — practice question

(a(i))[2]

Complete the chemical equation for the reaction. $\text{2Cu(NO}_3)_2 \rightarrow \text{O}_2 + \ldots\ldots\text{NO}_2 + \ldots\ldots\ldots\ldots$

(a(ii))[1]

Only oxygen gas is collected at X. Explain why this is so.

(b)[2]

Explain how nitrogen dioxide is formed in car engines.

(c(i))[2]

Calculate the number of moles of copper(II) nitrate present in the 18.8 g.

(c(ii))[1]

Calculate the maximum number of moles of oxygen that can be made by heating 18.8 g of copper(II) nitrate.

(c(iii))[1]

Calculate the maximum volume of oxygen at room temperature and pressure, in cm$^3$, that can be made by heating 18.8 g of copper(II) nitrate.

(d(i))[1]

Give the formula of the pale blue precipitate formed in test 1.

(d(ii))[3]

Explain the changes observed in test 2.

(d(iii))[2]

Identify the two reagents that need to be added to the aqueous copper(II) nitrate in test 3.

(e(i))[2]

Write a chemical equation for the reaction of copper(II) carbonate with nitric acid.

(e(ii))[1]

Carbon dioxide is added to the air by living things. Name the chemical process by which living things release carbon dioxide into the air.

(e(iii))[1]

Carbon dioxide is removed from the air by plants. Name the chemical process by which plants take carbon dioxide out of the air.

Worked solution & mark scheme

This 19-mark question has a full step-by-step worked solution and mark scheme. One marking point: 4NO2 → 2CuO

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