Question 1

Paper 2Easy6 marks

At room temperature, 0.0400 g0.0400\ \mathrm{g} of magnesium ribbon is added to excess dilute hydrochloric acid. Figure 1 shows the measured volume of gas collected over time.

010203040506070051015202530354045Time / sVolume of gas / cm³
(a)

Use Figure 1 to state the volume of gas collected after 30 s30\ \mathrm{s}

[1]
(b)

Write a balanced equation, including state symbols, for the reaction of magnesium with dilute hydrochloric acid.

[1]
(c)

In a voltaic cell, electrode A undergoes the reaction

\ceMg(s)−>Mg2+(aq)+2e−.\ce{Mg(s) -> Mg^{2+}(aq) + 2e^-}.

Identify electrode A as the anode or cathode and state its sign.

[2]
(d)

In an electrolytic cell, electrode B undergoes the reaction

\ce2H+(aq)+2e−−>H2(g).\ce{2H+(aq) + 2e^- -> H2(g)}.

Identify electrode B as the anode or cathode and state its sign.

[2]

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