Chemistry 0620 · IGCSE · Transition elements

Transition elements — practice question

Manganese is the element whose atomic number in the Periodic Table is 25. Calcium is the element whose atomic number in the Periodic Table is 20.
(a)[3]

Complete Table 5.1 so that it shows how many protons, neutrons and electrons are present in the $^{55}\text{Mn}$ atom and the $^{42}\text{Ca}^{2+}$ ion.

(b(i))[1]

Suggest why manganese is predicted to form coloured oxides.

(b(ii))[1]

State which other property of manganese is demonstrated by the formation of several oxides.

(b(iii))[1]

State the formula for manganese(II) oxide.

(c(i))[2]

Define the term reducing agent.

(c(ii))[2]

Complete the symbol equation by filling in the formula of the missing product and balancing the equation. $\dots\text{Mn}_3\text{O}_4 + \dots\text{Al} \rightarrow \dots + \dots\text{Mn}$

(d(i))[3]

Calculate the volume of chlorine gas produced, in cm^{3}, at r.t.p. when excess MnO₂ reacts with 50.0 cm^{3} of 0.200 mol/dm^{3} HCl. Follow these steps. Calculate the number of moles of HCl used. Determine the number of moles of Cl₂ formed. Calculate the volume of Cl₂ formed.

(d(ii))[1]

Describe a test for chlorine gas. test results

(d(iii))[3]

Explain, in terms of collision theory, why a fall in temperature lowers the rate of this reaction.

Worked solution & mark scheme

This 17-mark question has a full step-by-step worked solution and mark scheme. One marking point: Protons: 25 for Mn, 20 for Ca^{2}⁺

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