Inorganic Chemistry

State the approximate percentage by volume of oxygen in dry air.

A student heated zinc with copper(II) oxide and collected the following data: - Mass of zinc used: 0.15 g - Mass of copper(II) oxide used: 0.80 g - Mass of copper formed: 0.50 g Calculate the maximum mass of copper that can be obtained. (Relative atomic masses: Zn = 65, Cu = 63.5, O = 16)

Write the ionic equation (with state symbols) for the displacement reaction between zinc and copper(II) ions in solution.

Explain which substance is reduced in this reaction.

Describe one method for measuring the percentage of oxygen in air, including the apparatus used and the main steps.

A student adds iron filings to copper(II) sulfate solution. Write the full word equation for this reaction and explain what is observed.

Write the full ionic equation for the reaction and identify the spectator ions.

State the colour and physical state at room temperature for sodium and iodine.

Describe how you would distinguish between a sample of potassium metal and a sample of lithium metal using their observable physical properties.

Chlorine and sodium both have coloured vapours or solutions. Explain how the colour of chlorine gas compares with that of a solution containing iodine.

State the trend in colour observed down Group 1 and down Group 7 elements.

Describe what you would observe when a small piece of sodium is added to water. Give the word equation for the reaction.

Compare the observations when potassium is added to water with those for sodium.

State what you would observe when chlorine reacts with heated iron filings. Write the balanced chemical equation for the reaction.

A solution contains sodium chloride and potassium iodide. Describe how you could use chlorine water to show a displacement reaction occurs, stating your observations.

Explain why potassium is more reactive than sodium, referring to electronic structure.

The reaction between chlorine and iodide ions is a redox displacement. Write the ionic equation for this reaction and state which substance is oxidised and which is reduced.

Using electronic configurations, explain why chlorine is able to displace iodine from a solution of potassium iodide.

A student leaves a freshly cut piece of sodium exposed to air and measures how long it takes to lose its shine. Another student does the same for potassium. Explain, using observations and knowledge of the alkali metals’ reactions with air, which metal loses its shine faster and why.

The following table shows the time taken (in seconds) for lithium, sodium, and potassium to lose their shine when exposed to air:

When potassium reacts with bromine, a halide salt is formed. Write a balanced symbol equation for this reaction, including state symbols.

A displacement reaction occurs when chlorine water is added to a solution of potassium bromide. Use a labelled electron transfer diagram or a written explanation to describe how this reaction can be viewed as a redox reaction.

State the typical colour and solubility in water of sodium oxide.

Potassium manganate(VII) is a purple compound. State which ion gives rise to the colour, and what colour you would observe if pure potassium chloride is dissolved in water.

Predict the colour and physical state at room temperature of astatine, the halogen below iodine.

Predict whether sodium astatide would be soluble in water, and what colour its solution would be. Explain your reasoning.

Francium is an alkali metal that has not been observed directly. Predict two physical properties and one likely reaction with water of francium, based on trends in Group 1.

Explain in terms of electronic configuration why francium is expected to be more reactive than potassium.

The reactivity of halogens decreases down the group. Explain why, in terms of electronic configuration, chlorine reacts more readily than iodine.

Potassium reacts vigorously with water to produce potassium hydroxide and hydrogen gas. Write a balanced chemical equation for this reaction.

Describe one difference you would observe in the reaction of potassium with water compared to that of lithium with water.

Explain, using ideas about atomic structure, why potassium is more reactive than sodium.

Chlorine water is added to a solution of potassium iodide.